Meteors, aërolites, storms, and atmospheric phenomena

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LIBRARY

UNIVERSITY OF

CALIFORNIA
SANTA CRUZ

UNIVERSITY OF CALIFORNIA.

FROM THE LIBRARY Ol

BENJAMIN PARKE AVERY

GIFT OF MRS. AVERY.

August, 1806.

Accessions No.

METEORS,

AEROLITES, STORMS, AND ATMOSPHERIC
PHENOMENA.

FROM THE FRENCH OF

ZUECHEK AND MARGOLLfi.

BY

ILLUSTRATED

WILLIAM LACKLAND.

BY LEBRETOJf.

NEW YORK:

D. APPLETON AND COMPANY,
90, 92 & 94 GRAND STREET.

mo.

ENTBKED, according to act of Congress, in the year 1869, by

D. APPLETON & CO.,

in the Clerk's Office of the District Court of the United States for the
Southern District of New York.

M27/3

PRBF AC E.

THE nations of antiquity contemplated the
grand spectacles that Mature offers with emotions
different from ours. Their admiration partook
more largely of amazement and fear.

We read in the Vedas, or sacred books of
India, the following sentences :

" Will the sun rise again ?

" Will our beloved aurora return ?

" Will the powers of the night be conquered
by the god of day ? "

To us these questions seem strange. Were
they put in earnest ? Were the men of the ear-
liest ages serious when they asked themselves anx-
iously at night whether the light of day would
overcome the darkness, and reappear at dawn to
restore sunshine, heat, and life, to the world ?

4: PREFACE.

Yes, there is no doubt of it ; history attests the
fact ; the earliest nations thought that the stars
were animated, living bodies. In their eyes the
heavenly bodies were superior beings, good or
bad deities, friends or enemies, and ever ready to
engage in conflicts of which the issue might be
favorable or injurious to mortals.

The Aurora, or Dawn, itself was one of these
divinities, and the most charming of them. Al-
ways beautiful with freshness and youth, she was
ever saluted and hailed with gratitude, because
she it was who came the first to announce the de-
feat of the powers of darkness and evil, and each
morning, like a tender and faithful messenger,
awoke the sons of men.

It is not with these childlike feelings that we
moderns contemplate the sublime scenery of cre-
ation. We never entertain a doubt in our day
of the regular reappearance of the sun ; we know
beforehand the hour, the minute, nay, the very
second of his rising, and we can calculate with
precision the length of the dawn in different
climes. But this happy certainty, which we owe
to science and experience, has not weakened the

PREFACE. 5

sense of admiration in our souls. On the con-
trary, this religious and prolific feeling has in-
creased in strength, in elevation, and has become
more and more chastened as reflection and study
have gradually revealed to us, with greater force
of testimony, the infinite power and goodness, of
the Great Being who presides over the universe.
"We follow with an interest full of poetic thought
the progress of the human mind in the study of
these natural forces, these material agents, these
vast springs of life and motion, that obey the will ,
of God, and of which the ancients had only sa
confused an idea. How vast a field is here
opened to observation, even when limited to the
phenomena which have merely the terrestrial at-
mosphere for their theatre ! "What a variety of
effects are produced around us by the action, and
by the incessant combinations, of the three ele-
ments— air, fire, and water* — which serve to
maintain and develop life in all its grades and
in all its forms on the surface of the globe !

It has been said with truth by Ernest Faivre,

* Atmospheric phenomena are usually divided into aerial,
aqueous, or igneous meteors.

6 PREFACE.

in his book entitled " The Scientific Works of
Goethe : " " The spectacle of the various condi-
tions of the sky ; the changing aspects of the
clouds, the rain, the hail, and the tempest, as
they form above our heads ; the appearance of
luminous meteors, such as the aurora borealis,
the halo, and the rainbow, have in them some-
thing marvellous that enchains attention ; and
for an intelligence capable of deep appreciation
such studies must have a resistless charm."

CONTENTS.

CHAPTER I.

THE ILLUMINATION OF THE ATMOSPHERE. — TWILIGHT. — THE MIBAGE.

The Atmosphere.— The Azure Vault of the Sky.— The Prolongation of
Daylight.— Colors of the Spectrum.— Twilight in the Polar Regions.—
The Anti-Twilight.-The Mirage.— The Fata Morgana 13

CHAPTER H.

CLOUDS AND FOGS.

The Clouds.— Formation of the Clouds and Mists.— Influence of the Ma-
rine Currents. — Extraordinary Fogs. — Appearance and Motion of the
Clouds.— Hail-Clouds.— Forms of the Clouds.— Cloud-Rings.— Influ-
ence of the Mountains.— Distribution of the Clouds.— The Spectre of
the Brocken.— The Shadow of Mont Blanc... .. 34

CHAPTER III.

BAIN, SNOW, AND HAIL.

Dew.— White Frost.— The Distribution of Rain on the Surface of the
Globe.— The Great Rains of India.— Regions without Rain.— Influ-
ence of Forests.— The Softening of Climates.— Forms of the Snow.—
Flowers under the Snow.— Glaciers and Rivers.— Hail ... . . .61

8 CONTENTS.

CHAPTEK IV.

PHENOMENA OF THE GLAOIEBS.

Meteorology of the Glaciers.— Their Formation.— The Grindelwald and
Furca Glaciers. — Amphitheatres. — Neves. — Moraines. — Movements
of the Glaciers.— Primitive Glaciers.— Polar Glaciers.— Variations of
the Seasons and Climate . . 86

CHAPTER V.

THUNDER- STORMS.

Luminous Phenomena.— The Fires of St. Elmo.— Thunder-storms among
the Mountains. — The Forms of Lightning. — Globular Thunder- bolts. —
Thunder. — Singular Effects of Lightning. — Lightning-rods. — Geogra-
phy of Thunder-storms. — Influence of the Soil. — Volcanic Storms. —
Action of Thunder-storms upon the Subterranean Waters. — Utility
of Thunder-storms , .. 101

CHAPTER VI.

WHIRLWINDS.

Water-spouts.— Electric Whirlwinds.— Sand-storms.— Water-spouts at
Sea. — Water-spouts on Land. — Tornadoes. — Cyclones. — Hurri-
canes 139

CHAPTER VII.

RAINBOWS. — CROWNS, AND HALO8.

Description of the Kainbow.— Play of Light in the Drops of Water.—
Varied Appearances of the Arch.— Supplementary Arcs.— The Cir-
cles of Ulloa.— Crowns.— Colored Arcs.— Parhelia.— White Arcs.—
Anthelia.— The Halo of Clere ... . . 170

CONTENTS. y

CHAPTER VIII.

THE ATTOOBAL LIGHTS.

General Description.— Icy Fog.— Noise and Odor.— Electrical Currents.
—Magnetic Influence.— The Aurora Australia.— Different Points of
View.— Periodicity of the Auroral Lights 190

CHAPTER IX.

SHOOTING-STABS.

Fire-balls.— Showers of Stones.— Meteoric Stones.— An Extraordinary
Meteor.— Velocity and Appearance of Fire-balls.— The Fall of Aero-
lites.—Periodical Reappearances.— Composition of Aerolites.— Dark-
ening of the Sun.— Ring of Meteorites 207

CHAPTER X.

DUST IN THE ATMOSPHEBE. — DBY TOGS.

Cosmic Dust.— Volcanic Ashes.— The Sands of the Deserts.— The Red
Mists of Cape Verde.— Showers of Manure.— Dry Fogs 235

CHAPTER XI.

PBOGNOSTIOS OF THE WEATHEB.

Progress of Meteorology. — Foretelling the Weather. — Orpheus, Ho-
mer, Hesiod, Virgil. — Prognostics furnished hy Animals. — Prognos-
tics from Plants, and from the State of the Sky.— Characters of the
Seasons and of Future Tears.— Shooting-Stars.— Influence of the
Moon 261

CHAPTER XII.

PBAOTIOAL METEOBOLOGY.

The Brussels Conference.— Meteorological Practice. —Instruments of
Observation.— Telegraphic Meteorology.— The Hurricane of Decem-

10 CONTENTS.

ber 2, 1863. — Alarm-Signals. — Rural Meteorology. — Association for
the Advancement of Meteorology 286

NOTES.

INSTRUMENTS OF OBSERVATION.

The Barometer. — The Thermometer. — The Hygrometer. — The Pluvi-
or Udometer 319

LIST OF ILLUSTRATIONS.

PAGE

THE MIBAGE, 25

FATA MOBGANA, 30

CIEETJS AND STEATUS, » . 48

NIMBUS AND CUMULUS, 49

SPEOTEE OF THE BBOOKEN, 55

SHAPES OF SNOW-FLAKES, 77

THE LYSE-FIOBD, 131

A VOLCANIC STOEM, 133

A WATEB-SPOUT, 148

A HUEEICANE, . . . • • , .163
A BAJNBOW, ..... . . . 170

WATEBFALL EAINBOWS, 173

THE CIECLE OF ULLOA, 178

HALOS, 182

THE AUEOEA BOEEALIS, 190

THE HUEWOETH METEOE, 214

SHOWEE OF SHOOTING-STABS, 227

A WILL-O'-THE-WISP, 255

THE STOEM-GLASS, 294

ALAEM-SIGNALS, 306

THE PLUVIOMETEB, 323

METEORS AI^D METEORIC
PHENOMENA.

CHAPTER I.

TEE ILLUMINATION OF THE ATMOSPHERE.—
TWILIGHT.— THE MIRAGE.

The Atmosphere.— The Azure Vault of the Sky.— The Prolongation of
Daylight.— Colors of the Spectrum.— Twilight in the Polar Regions.—
The Anti-Twilight.— The Mirage— The Fata Morgana.

THE ATMOSPHERE.

" THE atmosphere surrounds the earth with a
spherical envelope, or wrapping, the thickness of
which is unknown.1

" However, numerous observations have indi-
cated that the limit of this atmospheric envelope
cannot be either less or more than a little over
sixty-two miles.

" This atmosphere, although invisible, presses
on the surface of our bodies at the rate of fifteen

1 It will always be impossible, perhaps, to attain a rigorously
accurate estimate, because the rarefaction of the upper layers
augments precisely as the height is greater and the pressure less.

14 METEOKS AND METEORIC PHENOMENA.

pounds per square inch, so that each of us carries
about, without feeling it, a total weight of nearly
35,000 pounds.

" Lighter than the lightest down, less palpable
than the most delicate filaments, it leaves intact
the spider's web, and hardly bends upon their
stalks the flowers that it refreshes with its dews ;
yet it bears with it around the world the ships of
all nations on its wings, and crushes the hardest
rock or metal with its weight. When in motion,
it is strong enough to uproot the loftiest trees,
and overturn the most substantial monuments, to
toss the ocean in furious billows, and shatter the
proudest vessels as though they were but toys.

" The atmosphere heats and cools, by turns,
the earth and all the creatures that inhabit it.

" It drinks up the mists which it holds aloft
in overarching clouds, and then showers them
down in rain or dew upon the thirsty ground.

" It refracts and reflects the rays of the sun,
in order that it may give us dawn and twilight,
and make the heavens glow with dazzling colors
when the great luminary rises and sets.

"Were it not for the atmosphere, the sun
would come to us and leave us abruptly, and we
should pass without transition from the gloom of
midnight to the blaze of noon. We should no

THE ATMOSPHERE. 15

longer enjoy the soft radiance of twilight, nor
would the clouds any longer shade the earth to
protect it from the burning heat of the day.

" The atmosphere brings us the elements that
sustain the flame of life, as they do the fire on
the hearth ; and it receives and transmutes in its
breast all the deleterious substances thrown off by
decomposition. By its circulation it brings us all
together in a common life of interchange and
mutual dependence. A gaseous substance which
would be fatal to us, to wit, the carbonic acid
which we constantly inhale and throw off, it dis-
perses over every part of the globe.

" The date-palms of the Nile, the cedars of
Lebanon, the cocoa-nut-trees of Tahiti, imbibe it to
improve their growth, and the palms and banana-
trees of Japan transform its poisonous breath
to flowers. That healthful substance, the oxygen
which we breathe, comes from the magnolias of
the Susquehanna ; the splendid trees that fringe
the Amazon and Orinoco; the giant rhododen-
drons of the Himalayas ; the roses and the myr-
tles of Cashmere ; the cinnamon-trees of Ceylon,
and the ancient forests that stud the interior of Af-
rica. All contribute to supply the agent of life." *

1 See Dr. Buist, in the Transactions of the Bombay Geographical
Society, vol. ix., 1850.

16 METEORS AND METEORIC PHENOMENA.

THE AZTJRE VAULT OF THE SKY. THE PROLONGATION

OF DAYLIGHT.

The uppermost regions of the atmosphere are
not illuminated by daylight. They are given over
to eternal night. At a certain height, we begin
to see the diffused radiance produced by the parti-
cles of the air acting on the rays of the sun, like
the thousand facets of a crystal, gradually die
out. To the eyes of aeronauts at the height of
eight or ten thousand feet above the earth's surface,
the stars seem to be shining through the deepest
night, while beneath them the earth is glowing
with the sun. The beautiful blue tint that appears
to us to belong to the sky itself is really only that
of the air beheld in masses. It grows darker
above the luminous region that immediately sur-
rounds us.

The vault that we seem to gaze upon does not
exist. The atmospheric layers, augmenting in
density as they approach the terrestrial surface,
lend this deceptive appearance to the sky. It
took a long time to overcome this illusion, and to
establish the fact that the form and the dimen-
sions of the celestial vault change with the condi-
tion of the atmosphere, its opaqueness or trans-
parency, and its greater or less degree of illumina-
tion.

THE AZURE VAULT OF THE SKY. 17

The rays of the sun are partly extinguished
in the air through which they pass. Their dim-
inution is much less at the zenith than at the
horizon, where they have to traverse a layer of the
atmosphere fifteen times as thick. Thus we can
fix our gaze upon the great luminary without be-
ing dazzled when it has just risen. A modifica-
tion of the same nature takes place in terrestrial
objects which are less and less easily seen as their
distance augments — " ' tis distance " " robes the
mountain in its azure hue."

This tint so peculiar to the atmosphere is fre-
quently altered by the watery particles which it
contains, and which generally throw off white
light ; this serves to explain the variations observ-
able in the sky where the blue is more decided at
the zenith than at the horizon. The color of the
same part of the sky often changes in the course
of the day. It grows deeper and deeper as we
advance from morning until noon, and then insen-
sibly fades until evening.

A very simple experiment will assist us in
comprehending that property of light which is
called refraction. Put a penny on the bottom of
a wide empty vase, or basin, and step back until
the coin is hidden from your view ; then, with-
out changing your position again, you will see the

METEORS AMD METEORIC PHENOMENA.

penny come into view whenever some water is
poured into the basin. This is because the light
follows a broken line, and the same thing happens
whenever it has to pass from a volume of air of
greater to one of less density. In like manner
may we explain that other phenomenon of the at-
mosphere which, by refracting the rays of the sun,
causes us to see it at a greater elevation than the
real one, and thus perceptibly increases the length
of the day.

Before rising, the sun illuminates the higher
ranges of cloud, and they reflect his light to us.
This light gradually increases until his disk ap-
pears. The directly opposite effect takes place in
the evening, when the sun is setting. Who has
not often admired those successive transitions,
those struggles between day and night, that offer
so sublime a spectacle, endlessly varied by the thou-
sand colors of the vapors spread along the horizon,
and the clouds that float in the sky ?

THE COLORS OF THE SOLAR SPECTRUM.

If we cause the solar light to pass through a
prism of crystal, it produces a colored spectrum.
This spreading forth of different hues, which has
an almost magical effect, is produced by the de-
composition of a white ray into several kinds of

THE COLORS OF THE SOLAE SPECTRUM:. 19

light, of which the seven principal hues follow each
other in the subjoined order :

Violet, indigo, blue, green, yellow, orange,
red.

That property of the atmosphere which pro-
duces this phenomenon is designated in science by
the name of dispersion.

Mr. Forbes, an English physiologist, has made
and described a very curious observation of the
play of light in vapors suspended in the air.
This observation assists us in comprehending the
phenomena visible during the morning and even-
ing twilight.

Mr. Forbes was standing near a locomotive that
was about to start, and was looking at the image
of the sun reflected in the column of steam that
issued from the 'scape-pipe.

Immediately over the orifice, the vapor was
clear and transparent like the air. The sun's rays
passed it without diminution of strength, and fell
upon a white wall opposite. A little higher up,
the light appeared less vivid, but the color was
orange, and the half shade thrown upon the wall
reminded the observer of the first tints of evening.
The disk of the sun just above it was of a deep-
red color. Beyond that the steam, before resolv-
ing itself into drops of water, would not allow

20 METEORS AND METEOKIC PHENOMENA.

the rays to pass, and its shadow was completely
dark.

SUNSET.

On the Atlantic Ocean, near the coast of
Portugal, we have noticed twilight in which the
colors of the spectrum succeeded each other with
great regularity, from bluish green to vivid red.
These modifications are slow in our climate ; they
permit us to enjoy fully the magic spectacle of
those twilight scenes in which the sombre blue of
the sea heightens the delicate hues of the sky.
Near the equator, the duration of the phenomenon
is much less, but it is generally extremely beauti-
ful. M. Liais, a French astronomer of eminence,
has thus described it in the narrative of his voy-
age to Rio Janeiro :

" Almost immediately after the setting of the
sun, a rosy tinge is seen in the east. Then there
soon becomes visible above it a dark segment of
sky, frequently of a greenish color. The rosy hue
extends and broadens toward north and south, and,
eleven minutes after its appearance in the east,
begins to be seen in the west, the zenith remaining
blue. In reality, a rosy coloring exists all aroTind
the zenith, clear to the horizon, excepting at the
east, where a grayish blue or greenish gray rests
on the horizon, and at the west, where a white

SUNSET. 21

segment may be noticed. Eight minutes after its
appearance in the west, the rosy coloring which
had remained all the time at the west, but was
gradually growing feebler, disappears altogether
on that side. At the west can be distinguished a
white segment, bordered with an arc of vivid rose-
color, above which appears the deep azure with
a splendor and intensity of tint impossible to
describe. This arc descends, gradually, toward
the horizon. It then becomes greatly flattened
and assumes a vivid scarlet or orange red. It
sets, at length, when the sun is 11° below the
horizon.

" When the red arc is very low, and on the
point of disappearing at the west, a second rosy
coloring appears gradually and simultaneously at
the west and the east, making a complete circuit
of the zenith, which remains blue all the time.
At the west, a space of silvery white separates the
two rose-colored arcs. By degrees, as the sun de-
scends, the second rosy coloring is seen to disap-
pear first at the east, withdrawing toward the
north and south without passing by the zenith.
Then, at last, the first rose-colored arc sets, and
there remains only the second arc, which is in
the west, and has the form of a flattened arch, with
a white segment below it. Finally, this second

22 METEOKS AND METEORIC PHENOMENA,

rose-colored arc, which assumes a still redder hue
as it descends, sets when the sun is 18° below the
horizon."

We will also quote the description of a sunset
on the Desert of Sahara, as given by M. Charles
Martins in the Revue des Deux Mondes, August
15, 1864 :

" Each sunset was a veritable feast for our eyes,
and a delight as well as a source of astonishment
for the mind, especially when the atmosphere was
not completely serene. The coloring of the sky is
then more vivid and more varied. Gradually, as
the sun approaches the horizon, the gray dishev-
elled clouds of the overarching sky — those latest
emissaries of the northern mists and fogs — become
fringed with purple tints that grow more and more
intense, while the rounded contours of the white
clouds reposing on the distant summits take on a
yellow bordering, and seem to be set and chased
in the rich gold that fills the western heavens. So
soon as the sun has descended below the horizon,
the softest ruddy tint spreads over the whole
western sky. An emanation of the departed lu-
minary, it colors all the mountains. One of these,
visible from Biskra, is called DjebelrHaminar-
Kreddou — the mountain with the rosy cheek. It
deserves this name, because, long after the setting

SUNSET. 23

of the sun, it retains a rosy hue, like the blush
of a young girl. Through the effect of contrast
with the red, the blue of the sky assumes a watery-
green tinge. Little by little the rose-color fades, the
illuminated arc contracts, and the light that shines
on it is as white and pure as that which should glow
in the realms of space beyond the limits of our at-
mosphere. Thanks to the transparency of the at-
mosphere, all the outlines of terrestrial objects are
clearly defined. The delicate edges of the leaves
of the palm-tree become more visible than in the
full light of day, and when the whole tree stands
out against these backgrounds of alternate yel-
low, red, and white, it seems as though the poetic
beauty of this noble plant were revealed, for the
first time, to the gaze. However, night comes on.
The planets and then the grand constellations
first appear ; the sky becomes peopled with myr-
iads of stars. The upper vault grows brighter,
and the milky way, which is but a dim, whitish
belt, as seen in the higher latitudes, looks like a
sparkling scarf of diamonds flung athwart the
celestial dome. The moon is no longer that pal-
lid star whose melancholy glance seems to sympa-
thize with the dulness of our foggy regions ; it is
a glowing disk of the purest silver, that reflects
without weakening the rays that it receives, or is

24 METEORS AND METEORIC PHENOMENA.

a crescent rounded off to the full orb, by the ashy
radiance which distinctly and sharply defines the
entire outline. Such was the sunset of December
13, 1863, on the evening before our departure from
Biskra ; it affected us deeply, for it was our adieu
to our evenings on the desert."

THE TWILIGHT OF THE POLAR REGIONS. THE ANTI-
TWILIGHT.

The rule generally admitted for the duration
of the twilight is the descent of the sun 18° below
the horizon. In many places, however, it lasts
all night, at certain periods of the year? In the
Scandinavian countries, in northern Germany,
and even as low down as the latitude of Paris,
this is the case about the period of the summer
solstice.

When the upper regions of the atmosphere
are filled with fine particles of ice, the darkness is
not complete even when the sun is 30° below the
horizon, as the long twilights of the polar regions
sufficiently prove. In those gloomy countries there
reigns, during the six months' night, a sort of half
daylight, which is sometimes strong enough to
read by, should the effulgence of the moon and
the radiance of the aurora borealis aid the pale
emanations of the sun.

'"

THE MIRAGE. 25

Yer y frequently one may notice, after the set-
ting of the sun, when one is standing on an emi-
nence, a red arch defined upon the eastern sky
around a darkish-blue space. Under favorable
circumstances, the line of separation is marked by
a yellowish edging. This is the phenomenon that
has been styled the anti-twilight. The apex, or
culminating point of the arch, is directly opposite
the sun, and attentive examination shows that the
segment illuminated only by the scattered rays
corresponds with the shadow of the earth pro-
jected against the sky.

THE MIRAGE.

If in summer we look at objects visible across
a field heated by the sun, they seem to waver and
their shapes continually change. This effect is
accounted for by the crossing and recrossing of
thin streams of cold and warm air rising and de-
scending. The luminous rays in passing through
them modify their movements at nearly every in-
stant.

The phenomenon known as the mirage, of
which the most remarkable examples are met
with in Egypt, have an analogous origin. In that
country the atmosphere is usually calm and ex-
tremely pure. At sunrise remote objects can be

26 METEOKS AND METEORIC PHENOMENA.

seen with the most perfect distinctness. From
the borders of the Nile to the limits of the Des-
ert, arise, from point to point, small eminences
crowned with villages and groves of palm-trees,
which look down upon each year's inundation of
the river. Gradually, as the sun climbs above the
horizon, the ground, becoming heated, imparts
its superior temperature to the lower strata of the
atmosphere. At such times, the undulating,
tremulous motion of which we have spoken is fre-
quently noticed. But when there is no wind, and
the dead calm of the atmosphere allows the lower
strata to expand without commingling with those
that are resting upon them, the spectator might
fancy that he had before him a huge lake, in
the midst of which are seen the reversed images
of the surrounding eminences and the villages
that are built upon them. The magnificent blue
sky seems to be reflected in it too; but, as one
approaches, the imaginary sheet of water fades
away, leaving only the burning sands in its place,
while farther on the same deceptive picture is
reproduced under a different aspect.

These appearances often misled the French
troops in Egypt. Worn out with forced marches,
dying of thirst under the scorching heat of an
African sun, and choked by the clouds of sand that

THE MIRAGE. 27

filled the air, they would rush headlong toward
the fancied water before them, but the delusive
shore, alas ! always fled farther and farther at their
approach.

To the distinguished savant Monge, who ac-
companied the French expedition into Egypt, is
due the elucidation of this phenomenon. He has
demonstrated that the most rarefied strata of air,
in this case, being the lowermost, a luminous
ray darting from an elevated object toward the
ground, deflects more and more in consequence of
refraction, up to the moment when it is reflected
from a last stratum, as it would be from a mirror,
and then rises again, subject to a series of refrac-
tions the reverse of those first encountered. It
thus at last strikes the eye of the observer in the
same direction as though it came from a point sit-
uated below the level of the soil, presenting the
reversed images as they would appear if he saw
them on the surface of a placid lake.

Mariners frequently get a view of the mirage
under circumstances the opposite of those that we
have just set forth. The temperature of the sea,
being colder than that of the superincumbent
strata of air, renders them less dense below than
above, and the reversed picture of distant shores
or vessels is defined on the atmosphere itself.

28 METEORS AND METEORIC PHENOMENA.

Captain Scoresby made many such observations
in the waters of Greenland.

" On the 19th of June, 1822," says this accom-
plished navigator, in one of his narratives, " the sun
was very warm, and the coast seemed suddenly
to come from fifteen to twenty miles nearer. The
highlands were raised so much to the view that we
could see them as well from the deck of the ship
as we could previously from the foretop. The ice
on the horizon assumed the most singular forms ;
huge blocks looked like pillars and columns ; the
icebergs and field-ice resembled a chain of pris-
matic rocks, and at many points the ice appeared
to be in the air at a considerable height above the
horizon. The ships that happened to be near us
had the most fantastic aspect. On some of them
the mainsail seemed to be reduced to a mere
nothing, while the foresail looked several times as
large as it really is.

" Above the vessels at a distance, we saw an ex-
act picture of themselves, but reversed and mag-
nified. In some cases this was at quite an eleva-
tion above the ship, but then it was always smaller
than the original. For some minutes we saw the
image of a vessel that was really below the horizon,
and one ship was surmounted by a picture of two
like it, the one upright and the other reversed."

THE MIRAGE. 29

Among the numerous varieties of this phe-
nomenon of the mirage, the one observed by
Messrs. Soret and Jurine on the Lake of Geneva,
which might be correctly styled the lateral or
horizontal mirage, is hot the least curious. These
gentlemen were at a window in the second story of
a house close to the shore, and were looking with
a spy-glass at a number of sail-boats passing from
right to left, in the middle of the lake, while,
nearer to the shore, the same fleet of boats ap-
peared to be sailing in exactly the opposite direc-
tion ! This was an illusion analogous to the
Egyptian mirage, and explicable in the same way.
Close to the shore the air had been in the shade a
part of the morning, and was comparatively cool-
er, while out in the open lake it had been heated
by the blaze of the sun. Hence, vertical strata
of air of different densities had remained motion-
less, or nearly so, in the prevailing calm, and re-
fraction had produced its magical effects from
side to side, instead of above and below, as in
the cases previously detailed.

When, instead of occurring in level and regu-
lar strata, these effects of refraction and reflection
take place in curved and irregular strata, a mi-
rage is produced in which the images are distorted
in every respect, broken or repeated over and over

30 METEORS AND METEORIC PHENOMENA.

again, and separated for considerable distances
from each other. This is what takes place in the
fantastic aerial vision formerly ascribed to the fairy
Fata Morgana, and sometimes attracts multitudes
to the sea-shore at Naples, and at Reggio on the
Sicilian coast.

" For an extent of several miles along the
coast of Sicily," says an eye-witness of this extraor-
dinary spectacle, " I &aw the sea assume the ap-
pearance of a chain of gloomy mountains, while
the waters in the direction of Calabria remained
perfectly smooth. Above them was seen, in
chiaro-oscurOj a range of many thousand pillars,
all of equal height, distance, and degrees of light
and shade. In the twinkling of an eye, these
pilasters lost half their height, and seemed to
bend over and resolve themselves into arches and
arcades like the old Eoman aqueducts. Then a
cornice formed along the top, and an endless num-
ber of castles, all alike, appeared. These pres-
ently faded away into towers that vanished also,
leaving nothing visible but a long colonnade, suc-
ceeded in its turn by windows, and then by pines
and cypresses also indefinitely repeated."

Sometimes these objects are depicted in the
sky at a great height above the ground. On such
occasions some of them are in rapid motion, while

THE MIRAGE. 31

others are at rest. Their outlines often gleam
with rainbow colors, and, as the light augments,
their form becomes more and more aerial, until
they melt away and disappear when the sun shines
forth in all his splendor.

Bernardin de Saint Pierre relates the follow-
ing incidents : " A very singular phenomenon
was once described to me by our celebrated paint-
er, Yernet, who was my friend. During his youth,
when in Italy, he devoted himself particularly to
the study of the sky, a more interesting branch
of his art, no doubt, than the study of the antique,
since it is from the sources of light that the colors
and aerial perspectives issue that form the charm
of pictures as well as of Nature itself. Yernet, in
order to fix their variations, had conceived the idea
of painting on the leaves of a book all the shad-
ings of each principal color, and then had marked
them with different numbers. When he was de-
signing a sky, after having sketched out his rough
draft and the forms of the clouds, he would rapid-
ly note down all the fugitive tints on his canvas
with figures corresponding to those in his book,
and then color them at his leisure. One day he
was greatly astonished to see in the sky the ap-
pearance of a city reversed. He could perfectly
distinguish the steeples, the towers, and the

32 METEORS AND METEOKIC PHENOMENA.

houses. He hurriedly made a sketch of the phe-
nomenon, and then, determined to know the cause
of it, he set out, following the direction of the wind,
into the mountains. But what was his surprise
when, some twenty miles distant, he found the
very city the spectre of which he had beheld in
the sky, and had a sketch of in his portfolio ! "

It is perhaps to the effects of mirage that we
must attribute the extraordinary faculty of sight
once so famous on the lie de Frcmce. Toward
the close of the last century, a colonist named
Bottineau could make out vessels which were still
a considerable distance below the horizon. The
new science which he pretended to have con-
structed, by combining the effects produced by dis-
tant objects upon the water and upon the atmos-
phere, he called Nauscopy. He went to Paris,
provided with letters from the intendant and the
governor of the island, attesting the reality of his
discovery ; but he could not even succeed in ob-
taining an audience with M. de Castries, who was
then Minister of Marine. No one took the pains
to investigate the means by which he mastered
such surprising results. In the latter, Arago was
not altogether an unbeliever, as we glean from his
efforts to discover whether certain phenomena of
the twilight, in which the shadows of distant

THE MIRAGE. 33

mountains probably play a part, would not help to
clear up this important secret. The poor colonist
returned to his home on the Isle of France, where
he was afterward seen passing most of his time,
until he died, on the sea-shore, his gaze fixed on
the horizon, and continuing to excite the amaze-
ment of all by the accuracy of his predictions.

CHAPTEE II.

CLOUDS AND FOGS.

The Clouds.— Formation of the Clonds and Mists.— Influence of the Ma-
rine Currents. — Extraordinary Fogs. — Appearance and Motion of the
Clouds.— Hail-Clouds.— Forms of the Clouds.— Cloud-Kings.— Influ-
ence of the Mountains.— Distribution of the Clouds.— The Spectre of
the Brocken.— The Shadow of Mont Blanc.

THE CLOUDS.

ARISTOPHANES, in his play of The Clouds, puts
the following invocation into the mouth of Soc-
rates :

" ' O sovereign master ! thou vast air that dost
envelop all parts of the earth ! — luminous ether !
and ye, O venerable goddesses, the clouds, mothers
of the thunder and the lightning ! — arise, O sover-
eign clouds ! and appear on the empyrean heights.
Come, O august clouds ! whether ye rest on the
sacred summits of Olympus, white with snow ; or,
in the plains of the Ocean, your father, ye form
dances in honor of the nymphs ; whether at the
mouths of the Mle ye dip up his waters in golden
urns, or whether ye dwell on the Palus Mseotis,

FORMATION OF THE CLOUDS AND MISTS. 35

or upon the stormy rock of Mimas, hearken to
my prayers, and receive with favor the sacrifice I
make.'

" Chorus of Clouds. — 4 Eternal clouds, from the
resounding bed of the Ocean, our father, let us
rise, in light, transparent mists, to the woody
summits of the lofty mountains, that we may look
down into the distance upon the hilly country ;
the sacred earth, prolific of fruits ; the courses of
the rivers, and the sea whose billows dash and
break roaring against the crags ! For the eye
of the heavens blazes eternally with dazzling efful-
gence. Let us scatter and dissolve these dull mists
that enfold us, and show ourselves to the earth
in our immortal beauty.' ':

The charm of this poetry lies in the truth as
well as the beauty of its images ; but the brief
meteorological sketch which Aristophanes then
gives, according to the theories of his epoch, is an
example of the errors that must follow observation
when not based, as it is to-day, upon knowledge
of the physical laws the influence of which we
are about to describe.

FORMATION OF THE CLOUDS AND MISTS.

The formation of mists and clouds is due to
the presence of watery vapor in an atmosphere

36 METEORS AND METEORIC PHENOMENA.

colder than the soil in which this vapor becomes
visible, exactly like the steam that rises over boil-
ing water.

The minute bodies of which the mist is com-
posed are hollow globules, resembling soap-bub-
bles, or droplets of water, the diameter of which,
measured through the microscope, is smaller in
summer than in winter. This diameter increases
also when rain is threatened.

Fogs being generally the result of the cooling
of the atmosphere, and of the mingling of two
currents of air of unequal temperature charged
with moisture, they are seen forming, especially at
morning and evening, and chiefly during the au-
tumnal season, over rivers and lakes, the water of
which is then much warmer than the atmosphere.

The formation of vapor is most abundant
when the air is the dampest. Kaemtz, in his
" Course of Meteorology," cites an observation
made by the ancients in reference to the volcano of
Stromboli : " When this volcano is covered with a
cloud, the inhabitants of the Lipari Islands know
that it will soon rain : but this does not happen,
as they suppose, because the volcano is more ac-
tive just before a shower ; it is because the air,
laden with watery vapor, cannot completely dis-
solve that which escapes from the crater."

INFLUENCE OF THE MARINE CURRENTS. 37

Columns of mist ascend sometimes at certain
points where the nature of the soil and vegetation
give rise to a more active evaporation.

After heavy rains, and when the sun shines
out again, these mists are seen appearing on the
slopes of the mountains, where the ground is
nearly always either arid or studded with woods,
and following the undulations and accidents of
the surface.

The same phenomenon occurs in Switzerland
above lakes the temperature of which is more or
less elevated, according to whether the streams
that feed them do or do not issue from the region
of eternal snow.

Mists form under circumstances also that are
different only in appearance ; for instance, when
there is a thaw, and the air, laden with humidity,
mingles with the colder air that is in contact with
the ice that still covers the waters. The same
cause produces the summer fogs seen along rivers,
especially after heavy storms of rain.

INFLUENCE OF THE MARINE CURRENTS.

Marine currents of elevated temperature, such
as the Gulf Stream, occasion frequent fogs on the
colder coasts against which they beat. The dense
fogs of Newfoundland and of the British Islands

38 METEORS AND METEORIC PHENOMENA.

are ascribable to this influence, which has been
noted in other regions — the Aleutian Isles, for
instance, lying in the track of the great tepid
current, analogous to the Gulf Stream, that crosses
the North Pacific.

Lieutenant De Haven, of the United States
Navy, during his expedition in search of Sir
John Franklin, saw, at the northern extremity of
Wellington Channel, a dense fog-bank motionless
and suspended in the air — a water-sky, rising, to
all appearance, above the Polar Sea, discovered in
1854 by Dr. Kane, the open waters of which are
tempered by the submarine current found to ex-
ist in Davis's Strait.

EXTRAORDINARY MISTS.

Mists are sometimes of remarkable extent and
duration. In 1821 and 1822 mists of this kind
occurred in England and France, so dense that
people could gaze upon the sun at noonday with
the naked eye. In 1783 a similar fog covered
nearly all Europe for the lapse of a month.

We read in a " Journal of the Reign of Henry
III.," published in the French language :

" On Sunday, the 24th of January, 1588, there
rose over the city of Paris and its environs so dense
a fog, lasting from noon until the next day, as

EXTRAORDINARY MISTS. 39

never was seen before within the memory of man.
It was so black and thick that two persons walk-
ing together in the streets could not see each other,
and were compelled to provide themselves with
torches, in order to recognize one another, when it
was not yet three o'clock. Yery many wild geese,
and other flying creatures of the air, were found
where they had fallen bewildered in the court-
yards of the houses, having dashed themselves
against the buildings and the chimneys."

Captain Berg, a Russian officer, mentions a
sort of mist that appears to rise from the sea in
stormy weather, and is called smoke. We have
repeatedly witnessed this phenomenon, which is
ascribable partly to electricity. M. Peltier, the
French savant, in one of his learned treatises,
divides mists into two classes, viz., the electric and
the non-electric. He explains the condition of the
former by the combined influences of the earth
and the higher regions of the atmosphere. More-
over, it has been ascertained that the electric fluid
is constantly developed in the atmosphere sur-
rounding cascades, where the water is incessantly
reduced to fine spray, and this remarkable phe-
nomenon might lead to a better determination of
the influence, no longer to be denied, of atmospheric
electricity on the formation of aqueous meteors.

40 METEORS AND METEORIC PHENOMENA.

Luminous mists are not uncommon. Mr.
Wartmaim, of Geneva, in a letter to M. Elie de
Beaumont, given in the Comptes Rendus of the
Academy of Sciences of Paris, for December 25,
1859, has described one of these strange meteors,
which continued to appear for nine successive
nights, viz., from the 18th to the 26th of Novem-
ber, 1859. The new moon, which was below the
horizon, could not contribute to this phenomenon.
The mist, which was very opaque, was still not
rnoist enough to dampen the ground. It threw
off light enough to enable one to distinguish the
smaller articles in a room where the observer
stood. A person who was proceeding on foot
from Geneva to Annemasse, in Savoy, on the 22d
of November, stated that he could see the road
during the night as well as he could have done by
the light of the moon.

Phosphorescent mists of the luminous order are
usually dry mists, like those of 1783 and 1831, to
which we shall refer again when we come to
igneous meteors.

Certain mists that form over marshy plains
have a peculiar odor, occasioned probably by the
miasma which they contain and bear along with
them.

In regions where it seldom rains, as for instance

APPEARANCE AND MOTION OF THE CLOUDS. 41

at Lima and around it, the mists caused by local
circumstances last sometimes for a part of the year,
serving to moisten the soil and maintain the fresh-
ness of the vegetation.

Mists are often seen forming over hollows
where the water is nearly always colder than the
air, and determines the collection of vapor above
it. Humboldt states that in the South Sea Islands
the shape of these mists frequently reproduces that
of the hollows exactly.

APPEARANCE AND MOTION OF THE CLOUDS.

The appearance and movements of the clouds,
the formation of which is due to the same causes
that produce the mists, are to be numbered among
the chief indications that announce to us the
changes brought about in the aerial ocean by the
variations of electric tension, temperature, and
humidity.

Mountain-summits are often enveloped in
clouds produced by the damp air, and by the
watery vapor that condenses by degrees as it rises
toward those colder regions. These clouds are
very frequently observed to disperse, as they get
farther away from the mountain-tops and encoun-
ter air-currents of a more elevated temperature.

" Often," says Kaemtz, " dark clouds pass rap-

42 METEORS AND METEOEIC PHENOMENA.

idly over the Hospice of Saint Gothard and pre-
cipitate themselves in heavy masses into the Val
Tremola. One would think, to look at them, that
all Lombardy was about to be buried under a
dense fog ; but, at the outlet of the Yal Tremola,
it is already dispersed by the warm currents of air
ascending."

During very violent winds, clouds are seen, in
consequence of like circumstances, clinging to the
peaks of mountain-ridges, and apparently motion-
less, while around those peaks the intervals re-
main perfectly clear.

The appearance of remarkable clouds suspend-
ed on the summits of lofty mountains sometimes
announces tempests, always preceded by atmos-
pheric variations, which practice in observing
natural signs teaches us to recognize. Thus,
the people of the Cape of Good Hope prognosti-
cate tempests from the southwest (so formidable
in their latitudes) whenever they see a compact,
lead-colored cloud gathering around the summits
of their highlands, and particularly on Table
Mountain.

ICE-CLOUDS.

The mists that form on the surface of the
ground, either in the depths of valleys or on the

ICE-CLOUDS. 43

heights, become clouds whenever, carried upward
by ascending currents, they remain suspended in
the atmosphere above us. Clouds are also formed
directly in the air by the meeting of two winds
laden with moisture and of unequal temperature,
or by the condensation of copious vapors which
rise toward the colder regions of the atmosphere.

Sometimes there are several beds of cloud
resting one above the other, and, generally, the
whiter they look, the higher they are.

The temperature of the regions that the clouds
ascend to is often several degrees below zero, and,
as may readily be understood, they are then com-
posed of icy particles, like the fine needles of the
mists that ascend in fleecy masses during severe
cold weather, and are often seen glistening in the
sunlight.

In reference to this subject we shall cite an
important observation that concerns meteorology
in the highest degree. It was enunciated in a re-
markable lecture on " the influence exerted upon
vegetation by the atmosphere."

The lecture in question was delivered by one
of the most learned and courageous scientific ex-
perimentalists of France, Professor J. A. Barral,
before the Chemical Society of Paris.

" On July 25, 1850, my friend M. Bixio and

44 METEORS AND METEOKIC PHENOMENA.

I were fortunate enough to ascend in a balloon
beyond the stratum attained by Gay-Lussac in
1804, and some surprise was manifested that we,
in the midst of a violently-agitated atmosphere^
and in the bosom of a vast ice-cloud, should have
found 39°. 7 (by the aid of numerous and delicate
instruments graduated by M. Regnault), or, in
other words, the temperature at which mercury
solidifies, in the same region where Gay-Lussac
had noted only 9°. 5, when the air was calm and
the sky clear. This surprise had no other basis
than a defective interpretation of the facts already
established. At the present day we have to ad-
mit that, even in the very highest regions of the
atmosphere that men have reached, there are con-
siderable variations in the temperature of the air
as well as upon the surface of the earth. A cir-
cumstance no less remarkable is, that, in mid-
summer, clouds of more than four thousand yards
in thickness, composed of numberless little needles
of ice, may be seen gliding above our heads at a
velocity of at least thirty miles an hour. In
those regions where eternal silence reigns, and
where all life has ceased, are condensed, along
with the last watery molecules that have mounted
from the bosom of the earth and the clouds, those
innumerable exhalations which we are wont to

ICE-CLOUDS. 45

term the impurities of the atmosphere. The mat-
ter contained in them descends again with the
rain, the hail, and the snow, to the surface of
our planet, where it is disseminated, and conveys
to the barrenest rock the elements necessary to
support vegetation, which may thus develop and
distribute themselves in nearly every latitude,
whatever may be the character of the soil that
receives the fertilizing shower. The lower aerial
strata that touch the surface of the solid crust of
our globe, and the doubly extensive surface of its
seas and oceans, after having become laden with
various materials, dilate by the effect of heat, and
then ascend until they meet the chill that con-
denses them in the higher regions, and causes
them to fall again to the surface. Thus a contin-
ual rising and falling motion is produced in that
atmospheric belt, between four and five miles in
thickness, which we have been able to sound. The
rain and the snow are formed, and, borne far
away from the spot which saw the birth of the
embryo cloud, they go forth to fertilize distant
plains by besprinkling them with water that is
saturated with a new air."

In England the latest winter ascensions of a
learned aeronaut, Mr. Glaisher, enabled him to

detect, at an elevation where the temperature was
3

46 METEORS AND METEORIC PHENOMENA.

very low during the summer ascensions, a current
of warm air, seven hundred yards in thickness,
charged with vapor. The latter soon afterward
descended upon the city of London and enveloped
it in a dense fog.

These interesting observations go to prove that
the loftier regions of the atmosphere are traversed,
like the depths of the ocean, by great currents of
unequal temperature, which, no doubt, contribute
to the maintenance of a general system of aerial
circulation, and which, sometimes descending to
the surface of the earth, there produce those great
changes of temperature that meteorological obser-
vation will one day, perhaps, enable us to foresee
with sufficient accuracy.

THE FORMS OF THE CLOUDS.

The causes which determine the forms, the
color, and the elevation of the clouds, are not yet
known. The double action of the currents of
warm air which ascend from the earth in the day-
time and the horizontal currents, suffices to ex-
plain the suspension in the atmosphere of the vis-
ible vapors, heavier as the latter are than the
medium in which they float. According to
Presnel, the solar heat absorbed by the clouds
makes a sort of balloon of them, which rises the

THE FORMS OF THE CLOUDS. 47

higher according to the greater elevation of the
temperature. It is owing to these influences that
clouds are generally higher at noon than toward
evening.

M. Jamin, in his course of lectures at the
Sorbonne, has demonstrated that the aqueous
particles whose aggregation makes a cloud, are in
the condition of full droplets, and that, when the
radius of these droplets is sufficiently small, but
little effort is required to sustain them at certain
heights. This effort is always supplied by the
continual displacements going on in the atmos-
phere.

Dr. Howard, a learned English writer on phys-
ical and meteorological science, was the first who
distinguished in the clouds the four leading forms
of Cirrus, Stratus, Nimbus, and Cumulus. He
classifies them in his " Essay on the Modifications
of Clouds, and on the Principles of their Produc-
tion, Suspension, and Destruction," published at
London in 1802.

The cirrus consists of thin, transparent clouds,
which look like delicate plumes, and are always
seen at a great height. They are sometimes ob-
served in parallel bands, or in filaments, stretching
north and south, appearing to diverge from one
point on the horizon and to converge toward an-

48

METEORS AND METEORIC PHENOMENA.

other diametrically opposite. " Many meteorolo-
gists," says M. Charles Martins, "for instance,

FORMS OF THE CLOUDS — THE CIRRUS, OB CAT-TAILS.

Howard, Forster, Peltier, and others, think that
the cirri serve as conductors between two distant

centres of electricity of different poles, in which
the fluid is seeking an equilibrium, and that the

THE FORMS OF THE CLOUDS. 49

flexibility of the clouds at length gives them the
rectilinear form required by the necessity for the
shortest possible transit from one focus to the
other. The whiteness of the cirri arises from
the icy particles and snow-flakes of which they
are composed. Their peculiar appearance has
earned for them the various titles of " cat-tails"

50 METEORS AND METEORIC PHENOMENA.

" horse-tails" " mackerel-sky" etc. They nearly
always portend a change of weather.

The stratus is the long horizontal belt of
smoke-colored clouds that often extends across the
horizon at sunset, and that may be seen forming,
on fine summer evenings, above expanses of
water and damp meadows. These cloudy bands
may be thick and extensive enough to cover the
sky, but they never yield rain.

The nimbus is a mass of dense, black clouds,
with jagged borders, which announce rain o'r
storm. Hence a cloud of any kind resolving it-
self into rain always takes the form of the nim-
bus.

The cumulus consists of what we may term
"the fine -weather clouds." Their whiteness,
which contrasts with the blue of the sky ; their
rounded, half-spherical forms ; their well-defined
outlines, make it easy to distinguish them. Piled
up on the horizon, they frequently assume the
shape of lofty snow-clad mountains, and when they
are seen to darken at the same time that the lower
bed of the cloud spreads out into a stratus, rain
may be expected.

The great poet Goethe, who was also a distin-
guished naturalist, has left us some remarkable
points relating to meteorology. We will quote a

THE FORMS OF THE CLOUDS. 51

passage from one of his learned essays on the sub-
ject, as epitomized by the French scwant Mar-
tins, who has edited the great German's scientific
lucubrations on natural history :

"When Goethe was made acquainted with
Howard's theory, he hastened to verify its princi-
ples, and to that end undertook a series of experi-
ments and observations. These observations were
chiefly made during the course of a journey in
Bohemia, between the 23d of April, 1820, and the
28th of May in the same year. They were ac-
companied by considerations of a general charac-
ter, to which we would, for a moment, call atten-
tion.

" Goethe, in common with many other mete-
orologists, distinguishes three regions in the atmos-
phere : the most elevated is characterized by its
dryness; it therefore tends to absorb the moist-
ure of the lower strata; and in this region the
sky is clear, or covered with a few clouds disposed
in the cirrus form. Goethe did not remark that,
in the icy heights of the atmosphere, the vapors
become converted into snow, and that the cirrus
is made up of masses of snow-flakes. In the in-
termediate regions we find the cumulus, whose
strange and ever-varying forms have become the
object of many superstitious notions among the

52 METEOES AND METEOEIC PHENOMENA.

dwellers in mountainous districts. Below the
cirrus and the cumulus extends the stratus, which
occupies the lowest part of the upper atmosphere.
" The higher and the lower regions are in a
state of perpetual conflict. Sometimes the upper
regions prevail, and the cumuli, being rent asunder,
rise and are scattered abroad in the form of fleecy
particles. Sometimes, on the other hand, the
lower region is the more powerful ; then, the
cumulus is lengthened out to a stratus, and the
heaped-up mass of clouds becomes a nimbus big
with rain. The formation of clouds may take an
opposite course : dense fogs ascend from the earth
in the shape of elongated strata, and group them-
selves into thick cumuli, or separate and form the
cirrus. Goethe holds persistently to this conflict
between the higher and lower regions of the at-
mosphere, and claims to have noticed that the
east and north winds cooperate with the action
of the upper regions, and those of the west and
south with the action of the lower layers."

DISTRIBUTION OP THE CLOUDS. THE CLOUD-EING.

The distribution of the clouds in different
parts of the globe has been too imperfectly ob-
served to enable us to deduce any general laws
therefrom. Moreover, this distribution is evi-

THE CLOUD-RING. 53

dently in direct relation to the quantity of rain
that falls in each region, and we shall presently
sum up the data thus far obtained in reference to
that branch of meteorology which relates directly
to cultivation and to the fertility of the soil.

This fertility is not due merely to the benefi-
cent action of the rain that waters our fields, nor
to the snow that protects them in winter. The
clouds, in spreading their mantle over the earth,
keep in its heat or prevent excessive drought,
and, as Maury has well said, in his "Physical
Geography and Meteorology of the Sea, " " when
their task is accomplished at one point, the winds
bear them away, to perform the same regulating
function elsewhere."

In the zone of the equatorial calms one
can best appreciate this influence of the clouds
upon climate and vegetation. "While in the re-
gion of the trade-winds, both north and south
of the equator, the sky is usually clear or dotted
with light clouds ; we, on the cootrary, when ap-
proaching the zone of calms, see the sky become
obscured and covered with dense vapors, arising
from the masses of air saturated with moisture
which the trade- winds continually sweep into that
zone. The dais or disk of clouds thus formed
extends around the globe like a ring, or belt, which

54 METEORS AND METEORIC PHENOMENA.

is carried from the north to the south, or from the
south to the north, within certain limits, accord-
ing to the season, alternately protecting the dif-
ferent parallels that it covers from the blaze of
the sun, and bringing them rain at given periods.

INFLUENCE OF MOUNTAINS. THE SPECTRE OF THE

BROCKEN.

We have already referred to the influence ex-
erted by mountains on the condensation of vapors.
M. de Gasparin, in his "Rural Meteorology,"
cites quite a remarkable observation in connection
with this subject. " It is known," says he," that
the narrow passage leading into the harbor of
Plymouth is bounded on the east and west by
two promontories covered with woods. J. Har-
vey has noticed that a dense and quite compact
cloud, coming from the west, disappeared in pass-
ing over the strait and formed again upon reach-
ing the opposite point of land."

The abundance of clouds in mountainous
countries, their capricious forms, and frequently
strange distortions, have furnished geniuses and
poets with beautiful similes. Popular traditions
show us that these natural phenomena have long
been the source of superstitions that have not yet
entirely died out. Thus, in certain parts of the

THE SPECTRE OF THE BROCKEN. 55

"V osges Mountains, the long, black trains of clouds
that unroll and wind fiercely down through the
deep gorges, at the approach of storms, still in-
spire terror, as a token of the presence of evil
spirits sweeping by with the tempest.

A wonderful phenomenon, the Spectre of the
Brocken, was long explained by a superstitious
peasantry as the work of direct supernatural in-
tervention. One of the best descriptions of this
phenomenon was given by Mr. Hane, who wit-
nessed it on May 25, 1797 : " After having scaled
the summit of the mountain more than thirty
times, in vain, at last he had the good fortune to
see the object of his curiosity. The sun rose at
about four o'clock in the morning, and the weather
was fine. The wind was driving before it toward
the west masses of transparent vapor, which had
not yet had time to condense into clouds. About
a quarter-past four, the traveller saw, in the di-
rection of Achtermannshohe, a human figure of
enormous dimensions. A gust of wind having
nearly blown away Mr. Hane's hat, he quickly
put up his hand to retain it, and the strange fig-
ure made the same gesture. Mr. Hane then im-
mediately made another motion, stooping down-
ward, and this act was likewise reproduced by the
spectre. Another person joined Mr. Hane, at

56 METEORS AND METEORIC PHENOMENA.

this moment, and the two gentlemen, placing
themself together on the very spot from which
the apparition had been noticed, looked toward
Achtermannshohe, but saw nothing. However, a
little while afterward, two colossal figures ap-
peared in the same direction imitating the motions
and gestures of the two observers, and then dis-
appeared. They showed themselves again, a little
later, accompanied by a third figure. Sometimes
these shapes were feeble and indistinct ; at others
they were very intensely marked and their out-
lines sharply defined. The reader will have
guessed that the phenomenon was produced by
the shadow of the spectators projected on a cloud.
The third figure was undoubtedly due to a third
person half hidden behind some broken mass of
rock."

During his journey with La Condamine
among the Cordilleras, Bouguer, a member of the
French Academy of Sciences, sent out with the
former to South America to measure a degree of
the earth's surface, witnessed a phenomenon,
similar to the one just described, from the sum-
mit of Pambamarca :

" What astonished us," says he, " was that the
head of the shadow was adorned with a halo
formed of three or four small concentric crowns

THE SPECTRE OF THE BEOCKEN. 57

of very vivid color, each one with the same vari-
ety as the first rainbow, the red on the outside.
This made a sort of apotheosis for each spectator,
and I must not forget to add that each of them
tranquilly enjoyed the pleasure of seeing him-
self decorated with all these crowns, without even
catching a glimpse of those of his neighbors."

Kaemtz has verified the same thing on the
Alps. So soon as the shadow was projected on a
cloud, the head was seen surrounded by a lumi-
nous halo. Scoresby in the polar regions, Ramond
in the Pyrenees, and De Saussure, have all seen
and described this curious phenomenon, which is
known under the name of Anthelia.

Sometimes it is observed under more ordinary
circumstances, at the rising and the setting of the
sun, when fogs are resting on the ground. Fre-
quently the aerial figure, the head of which is al-
most always surrounded with luminous rays, is
no larger than life. It may be readily conceived
that such apparitions gave rise to the quaint le-
gends heard in different countries, particularly in
mountainous regions where the lofty summits,
crowned with clouds of varying outline and ever-
changing colors, have played so grand a part in
the composition of religions fables.

When the sun is just at the horizon, one may,

58 METEORS AND METEORIC PHENOMENA.

if standing close to a railway, see the shadows of
the telegraph-posts appear on the long pennant of
white steam that rises from the locomotive, and
floats over the train. Aeronauts often see the
magnified image of their balloon upon the clouds,
in the elevated regions through which they pass.
The phenomenon is in every case of the same gen-
eral nature as the famous Spectre of the Brocken.

THE SHADOW OF MONT BLANC.

When the spectator happens to be standing on
the summit of a very high mountain, the shadow
projected by the setting sun is directed upward
to the sky, and sometimes produces a magnificent
phenomenon, which was observed by Messrs.
Bravais and Martins in one of their scientific
excursions to Mont Blanc. M. Bravais has
given the following description of it :

" As the sun was approaching the moment of
his setting, we looked in the direction opposite to
the luminary, and beheld, not without some sur-
prise, the shadow of Mont Blanc defined upon the
snow-clad mountains in the eastern part of the
panorama before us. It gradually rose in the at-
mosphere until it attained the height of an entire
degree, remaining all the while distinctly visible.

" The air above the apex of the shadow was

THE SHADOW OF MONT BLANC. 59

tinged with that purply rose-color, which one sees,
in fine sunsets, suffusing the loftiest peaks. The
edge of this color presented a zone of deeper in-
tensity, and that continuous bordering enhanced
the splendor of the phenomenon.

" Let any one imagine the mountains in the
great valley of Aosta projecting their shadows at
one and the same moment upon the atmosphere,
the lower part dark with a slight greenish tinge,
and, above each of these shadows, a breadth of
purply rose-color, with a belt of deep rosy-red sep-
arating it from them ; let him add to that the
sharp uprightness of the cones and peaks in the
shadow, especially of their uppermost ridges, and,
finally, the effects of perspective, making all these
lines converge one upon the other toward the
very summit of the shadow of Mont Blanc, that is
to say, toward that point in the sky where the
shadows of our bodies should be. Even then he
will have but an incomplete idea of the richness
of the meteorological phenomenon that developed
itself before us for some moments. It seemed as
though an invisible being were in a throne girt
round with fire, and that, on their knees, angels
with glittering wings were worshipping him, all
bending their forms toward him. At the sight of
a spectacle so magnificent our arms and those of

60 METEOES AND METEORIC PHENOMENA.

our guides dropped motionless, and cries of enthu-
siasm escaped our lips. I have seen the superb
aurora borealis of the north, with its crowns in
the zenith, and its variegated wavering colon-
nades of pillars, far surpassing the finest devices
of our pyrotechnists, but the spectacle presented
by the shadow of Mont Blanc, in my opinion,
went beyond them all."

CHAPTEE III.

RAIN, SNOW, AND HAIL.

Dew.— White Frost.— The Distribution of Rain on the Surface of tho
Globe.— The Great Rains of India.— Regions without Rain.— Influ-
ence of Forests.— The Softening of Climates — Forms of the Snow.—
Flowers under the Snow.— Glaciers and Rivers.— Hail.

DEW AND WHITE FROST.

DEW — the bright deposit of limpid little drops
which glisten in the morning light on the foliage,
like pearls and diamonds — is caused by the con-
densation of atmospheric vapor on substances suf-
ficiently cooled during the night by radiation, or
the loss of heat through the air. Doctor "Wells,
an English physician, was the first to give this ex-
planation, after a great number of experiments.

A lock of very dry wool weighing 10 grains,
placed upon a plank sustained by four uprights,
increased its weight only two grains by moisture,
while a similar lock placed above it gained 14
grains, and another, laid on the grass, increased

62 METEORS AND METEORIC PHENOMENA.

16 grains. Thermometers substituted for these
locks of wool exhibited the lowest range where the
dew fell the most copiously. On the other hand,
substances that do not so readily part with their
caloric, such as the metals, remained dry, while
others of greater radiating power lying close be-
side them were covered with dew. A clear sky
was found to be favorable to the cooling process,
and consequently to the deposit of dew ; and the
passing of a cloud, which gives heat for heat, was
sufficient to arrest the phenomenon. Moreover, it
was observed that less dew formed in the depth
of valleys than on the tops of hills, from which a
greater extent of clear sky could be perceived.

When the nocturnal radiation causes the tem-
perature of a body to descend below zero, the
watery vapor condenses into ice, and white frost
is deposited instead of dew. A custom prevalent
in India may serve to give an idea of the power
oi this cooling process. Ice is habitually procured
there by exposing shallow pails, filled with water,
and isolated from the terrestrial heat by layers of
loose straw laid beneath them, in some open
place, during very clear nights. Under these
conditions the temperature of water has been
known to fall IT degrees.

In order to protect plants from the disastrous

DISTRIBUTION OF BAIN ON THE GLOBE. 63

effects of these frosts, it suffices to arrange a hor-
izontal screen about two yards above the ground,
to prevent radiation. In the open field, during the
clear nights of the end of April and the beginning
of May, the cold often destroys the buds of plants.
This occurs when the moon shines in an uncloud-
ed sky, but, should the latter be obscured, no such
bad effects are observed.

The russet or " red moon " is thus explained :
The luminary of night is often most wrongfully
blamed by country-people, since it is really the
serenity of the sky which is the cause of the hurt-
ful chill, and the consequent loss of crops.

THE DISTRIBUTION OF RAIN ON THE GLOBED
SURFACE.

The refreshing stimulus extended to plants by
fogs and dew is but temporary. A humidity
much more abundant is required by them. Al-
though there are very heavy dews in Egypt, the
vegetation of that country would soon disappear
were it not that the inundations of the Nile make
up for the extreme rarity of rain. In years when
the overflow is but limited, those districts which
it does not touch remain sterile. Farmers every-
where, whether fearing an excess of moisture or
of drought, attach great importance to the rain,

64 METEORS AND METEORIC PHENOMENA.

its quantity and its distribution throughout the
seasons of the year.

Rain falls sometimes when no cloud is visible,
and the sky is perfectly clear. Yarious observa-
tions of this nature are cited by Humboldt and
Arago. " The night was fine," says a savant of
Geneva, " and the stars were shining with their
ordinary brightness, when a rain composed of
large, tepid drops fell over the city for six min-
utes." The same phenomenon is reported by an
eye-witness to have taken place at Constantine at
noon, and with the sky magnificently blue and
clear.

But usually it is after having passed through
the cloudy form that the moisture of the atmos-
phere precipitates itself, and the indications con-
tained in the preceding chapter give the first ele-
ments of the geographical distribution of rain.

To commence with, we have the equatorial
zone, enveloped in its girdle of clouds, formed not
only by the vapors arising from the warm waters
of the ocean carried up by powerful ascending
currents, but also by those that the trade- winds
sweep thither from north and south. This is a
region where rain falls every day and in great
abundance, the mixture of the masses of saturated
air with the cold atmospheric layers taking place

DISTRIBUTION OF BAIN ON THE GLOBE. 65

continually under a very hot sun. Mention has
been made of calms sufficiently prolonged and ac-
companied by rains heavy enough to make the
water fresh on the surface of the sea. The mar-
iner is shy of these latitudes, where the tepid and
heavy atmosphere causes an irresistible languor
and develops dangerous diseases. Storms are so
frequent there thai; it is rarely one does not hear
the thunder rumbling above the dense clouds with
an echo like the fiercest electric explosions among
mountains. The familiar expression Hacking-pot,
so often on the lips of sailors, very appropriately
conveys the effect of the sombre belt thus de-
scribed after the unvarying blue of the trade- wind
skies.

All the vapor disengaged in this immense
equatorial boiler does not fall in rain at the same
place. Atmospheric currents higher up than the
trade- winds carry it toward the two poles. They
come in contact with the surface of the earth in a
region the limits of which vary with the annual
advance of the sun, like those of the equatorial
belt of clouds, and which, as a general thing, is
fixed in the tropics. Places situated in this
region have periodical rainy seasons called win-
terings.

In our temperate latitudes, the commingling

66 METEORS AND METEORIC PHENOMENA.

of layers which produces the rain ceases to be the
result of ascending currents meeting with the
upper cold air. It is produced by horizontal cur-
rents, the direction of which is generally opposite
to each other. This rain falls at all periods of
the year.

At the 60th degree of latitude we reach the
circumpolar zone, where no rain falls in winter,
owing to the extreme rarefaction of the limpid
atmosphere, which extends over the immense ex-
panse of snow, and no fogs are seen to form, ex-
cepting in those regions where the water is open.

If we compare the system of the circulation
of the waters upon the surface of the globe to an
alembic with the fire at the equator, we shall see
that the regions outside of the tropics perform the
part of condensers. Lieutenant Maury has very
strikingly illustrated the functions of this admira-
ble apparatus. " The average amount of rain that
falls annually upon the surface of our globe," he
says, " has been estimated at 1.5 yards in depth ;
Thus, then, to raise enough of water from the
ocean, every year, in the form of vapor, to cover
the earth with a spherical coating 1.5 yards deep ;
to carry that watery vapor from one zone to
another, and then to precipitate it in different
forms at certain determinate points at chosen

THE GREAT BAINS OF INDIA. 67

epochs, and in appropriate quantities, such are
the functions of the great atmospheric machine.
The water vaporized in this manner being taken
principally from the torrid zone, the atmosphere
in that zone alone must absorb a liquid mass of
nearly 5 yards in thickness, and 3,000 marine miles
in breadth, upon a development of 24,000 miles ;
raise it as high as the clouds, and then let it fall
again upon the earth. This it must, moreover,
do every year ! What a wondrous and powerful
mechanism, then, is this atmosphere of ours, and
how harmoniously its different elements must be
combined in order that this work, which over-
whelms the imagination, may be carried on with-
out the slightest disarrangement ever manifesting
itself in a totality of functions as complex as they
are varied ! "

THE GREAT RAINS OF INDIA.

The regions where the monsoons prevail have
an exceptional pluvial arrangement. In the month
of April, the season of the northeast trade-winds
closes in India. The vast deserts of Central Asia,
heated by the sun, give a sort of breathing aspira-
tion that produces the southwest monsoons. La-
den with the vapors of the ocean and of the Ara-
bian Gulf, these winds strike the Ghaut range of

68 METEOES AND METEORIC PHENOMENA.

mountains at right . angles, and there deposit an
extraordinary quantity of rain, which Johnson tells
us has been known to attain the enormous meas-
urement of 14i inches in a single day. They
then diverge toward the Himalayas, where the
temperature is lower than on the summits of the
Ghauts. There they abandon in the form of snow
and rain nearly all the moisture with which they
were charged, and thus it happens that, when they
reach the arid wastes beyond those mountains,
they rarely have enough vapor left to form clouds.
It is at Cherrapondschi, among the Himalayas,
that the maximum of rain-fall, viz., 17" yards per
annum, has been found for the entire globe.

Owing to these rains, vegetation attains a
prodigious development in India ; but they are
accompanied by all sorts of pests, as Mr. D. War-
ren graphically describes them in his work on
British India.

"A suffocating calm," he says, "which pre-
vails particularly about the end of the great
heats, precedes the setting in of the southern mon-
soon. With the end of May come on the first
storms, which are brief, but of extreme violence.
Thunder is heard in the distance at intervals ; the
sun sets in a bed of clouds, and every evening
the lightnings illuminate all points of the horizon.

THE GREAT RAINS OF INDIA. 69

The rain falls, for half an hour, in torrents ; after
a few days it lasts longer, and toward the middle
of June it rules the entire day, for, when it is
not actually raining, the sky is at least covered
with a dense and threatening curtain of clouds.
It rains sometimes, particularly in July, for thirty
or forty hours consecutively, and then not in fine
lines, broken and almost imperceptible, as in our
climates, but in straight, parallel streaks, and
frequently like a sheet of water coming down all
at once with the fury and impetuosity of a cas-
cade.

" The miserable clay-huts of the natives become
thoroughly soaked under this continual avalanche ;
their roofs fall in and bury them, or, at all events,
escaping that easier fate, they find themselves ex-
posed to all the rigors of the open air, and perish
in great numbers. This is the period of wide-
spread distress, which does not spare even the
nabob and the conqueror ; and the very reptiles,
those of the most hateful species, like the rest, in-
undated in their holes, dart to the surface of the
soil and seek an asylum among the dwellings of
men. Numerous varieties of snakes, centipedes,
and . scorpions, climb your stairs, invade your
houses, and glide into every room. It is impossi-
ble to take a step in one's bedchamber at night

70 METEORS AND METEORIC PHENOMENA.

without a light, unless one is prepared to run the
risk of a sting that may prove fatal. The utmost
distrust must be felt of every thing that one touch-
es ; a cruel bite may kill you from the inside of a
boot or a sleeve. For some time you lead a life
of continual alarm and disgusting contacts; but
these annoyances are not of long duration. The
monsoon begins to decline in the month of Au-
gust, and dies away in the first days of Septem-
ber. The five months that follow, until the be-
ginning of February, are delicious, and make one
forget those that went before ; there is rapture in
the mere fact of existence, the air is so fresh and
the face of Nature so lovely."

KEaiONS WITHOUT RAIN.

There are parts of the globe's surface where
rain is almost unknown. Such are the coasts of
Peru, and it is easy to discover the reason. They
lie within the sweep of the southeast trade-
winds. The latter traverse the Atlantic and
there become laden with vapors, which they then
deposit on their trip across the American Conti-
nent, where the rain feeds the sources of the Rio
de la Plata and the southern affluents of. the
Amazon. Then, they pass on to the snowy
peaks of the Cordilleras, where the low tempera-

REGIONS WITHOUT EAIN. 71

ture completely divests them of tlie moisture they
may still have retained. We need not be sur-
prised, then, that they are dry and cold when
they sweep down the western slope of the Andes,
and remain so until they meet the waters of the
Pacific Ocean.

A large part of Australia also is in the track
of the southeast trade-winds, and should have
large rivers, like that intertropical portion of
South America just mentioned ; but the contrary
is the case. Maury explains this difference by
the relations that exist between the direction
of the winds and that of the coasts. " In Aus-
tralia," he says, "the eastern coast runs in the
direction of the trade-winds, while in South
America it is perpendicular to that line. Conse-
quently, in Australia, these winds only fringe the
coast, so to speak, with their vapors, and dis-
pense their rains over these parched lands so
sparingly, that the trees, in order to retain the
small amount of moisture allotted to them, are
obliged to arrange their leaves in the same line
as the rays of the sun, since, if they were in the
natural position, they would be too quickly dried
up. On the contrary, in South America, where
the winds blow in a direction perpendicular to
the shore, and cause the humidity with which

72 METEORS AND METEORIC PHENOMENA.

they are charged to penetrate to the heart of the
country, one sees the leaves striving, as it were,
to reach the sun's rays and present themselves to
them in their fullest development."

The Desert of Sahara, situated in the domain
of the trade-winds that cross the land only, is de-
nied rain entirely, and shows us what our globe
would be without the magnificent reservoir of
the ocean. From the immense sandy plains of
Africa there rises only a column of burning air,
while not even a drop of dew falls to moisten the
parched surface and there develop vegetation.

THE INFLUENCE OF FOKESTS.

The influence of forests, in reference to rain,
has been established by numerous observations.
Columbus mentions it in his "Journal of the
Yoyage to America," where he attributes to the
density and extent of the forests that covered the
mountain-sides the abundance of rain to which
he was so long exposed while coasting along the
shores of Jamaica. He remarks that "formerly
rain was no less abundant at Madeira and on
the Canaries and Azores, but since the trees that
gave shade have been cut down, it has become
much less frequent in those countries."

Humboldt demonstrates that there exists a

THE INFLUENCE OF FORESTS. 73

frigorific radiation above wooded regions, that
must condense the vapors. The summits of
mountains covered with forests become enveloped
with mists oftener than those of mountains that
are bare, and springs of water are more frequent-
ly found among them. Numerous plantations of
trees in Egypt have caused the rains that had
totally ceased to reappear — a fact that deserves
especial mention. In some parts of the Antilles
the clearing of portions of the soil has diminished
the quantity of rain, and the watercourses have
lost their abundance.

At Porto Rico a different plan has been pur-
sued. A decree of the King of Spain prescribed
that, every time a tree should be cut down, three
should be planted for it, and the country has con-
sequently retained its high fertility. The beauty
of the soil and the abundance of water have left
the land more productive than on the adjacent
islands.

We extract from the scientific work of M.
Boussingault a passage confirming the existence
of similar relations between the clearing away
of the woods and the quantity of water: "In
the valley of Cauca," he says, " it is well known
that such and such a district, whose soil and me-
dium temperature are favorable to the cultivation

74: METEOES AND METEOEIC PHENOMENA.

of the cacao-tree, still gives no good result if the
latter be placed too near to the forest. But, when
these forest-lands are cleared, and transformed to
fields of yucca, sugar-cane, and maize, the cacao-
tree flourishes remarkably. The following fact
was obtained from Don Sebastian Marisansena, a
resident of Cartago. Haying procured the title
of capitan poblador to found a village at La
Balsd, at the foot of the Quindin range, he began
by putting in a plantation of cocoa-trees. Dur-
ing the first ten years the crops amounted to
little or nothing, because the rains were too fre-
quent. The hacienda, or farm, began to be pro-
ductive only when the inhabitants of La Balsd
were numerous enough to make the clearings ex-
tensive. Then at length the sun could ripen the
cacao. In 1816, political events led to a large
emigration of the people, only the negroes re-
maining on the farm. Six years later, the sur-
rounding fields were again transformed to forests ;
the crops diminished more and more, and in
1827, when I passed through La Balsd, they had
not gathered any cacao for three years."

AMELIOEATION OF CLIMATE.

The clouds when they dissolve in rain restore
to the atmosphere all the heat that was taken up

AMELIORATION OF CLIMATE. 75

in forming them. Every one may have observed
the increased mildness of the atmosphere after a
shower of some duration. This circumstance
powerfully affects the climates of the higher lati-
tudes, especially in the southern hemisphere, where
the counter trade-winds of the northwest con-
dense their abundant vapors. It has been ob-
served that, relatively to their position, the south-
ern Shetlands have no very cold winters ; a fact
undoubtedly due to the great quantity of heat
disengaged during the rains.

The quantity of rain that falls on the western
slope of the Patagonian Andes (and, according to
Admiral Fitzroy,. it amounts to more than four
yards in forty days) imparts a remarkable degree
of heat to the winds that descend upon the other
slope. It is to them, as well as to a feeble oce-
anic current, that the extraordinary climate of the
Falkland Islands is to be attributed. These isl-
ands are in a latitude corresponding to the rude
regions of Labrador, and yet cattle pass the winter
there in the midst of fine pasture.

In North America, at the base and on the
slopes of the Rocky Mountains, where the Mis-
souri takes its rise, there is a phenomenon ob-
servable that must be ascribed to the heat disen-
gaged by the great condensation that takes place

76 METEORS AND METEORIC PHENOMENA.

when the western winds of the Pacific strike the
summits of the chain. In winter, navigation is
open on the upper part of the river, while lower
down it is entirely closed by the ice. At a very
considerable elevation, a spring temperature is
enjoyed, and the country is covered with rich
verdure, at the very moment when the severest
cold prevails in the distant plains below.

FORMS OF THE SNOW.

When a current of very cold air penetrates
to a warm apartment suddenly, it may produce
snow, if the room be full of watery vapor. The
story is told that, upon one occasion in St. Peters-
burg, a pane of glass was accidentally broken in
the window of a saloon where a large party was
assembled, and a gust of wind bursting in through
the orifice, congealed the vapors of the room and
scattered them over the astonished guests in the
shape of snow-flakes. Similar effects have been
noticed in Siberia and Nova Zembla.

Whenever the temperature of the clouds falls
below zero, their drops congeal and form snow,
which then falls through the air in flakes until it
strikes the ground. These flakes, when caught
upon a black surface and examined through the
microscope, exhibit a remarkable regularity of

FOKMS OF THE SNOW.

77

form that long since attracted the attention of
observers. Kepler speaks of their structure with
lively admiration, and, since his day, these grace-
ful crystallizations have been described with care.

FORMS OF SNOW-CRYSTALS.

Yet, notwithstanding their great variety, they de-
pend upon extremely simple laws. " These snow
crystals," says Tyndall, " being formed in a calm

78 METEORS AND METEORIC PHENOMENA.

atmosphere, are constructed on the same model :
their molecules group together to form hexagonal
stars. From a central nucleus project six needles
that, together, form an angle of 60 degrees. From
these central needles there shoot out other small-
er ones to the right and the left, in their turn de-
scribing with infallible fidelity their angle of 60
degrees. These six-leaved flowers assume the
most varied and wondrous forms. They are pat-
terned in the finest gauzy films, and all around
their angles are sometimes seen rosettes of still
more microscopic dimensions. Beauty superadds
itself to beauty, as though, when once at work,
Nature took pleasure in showing, even in the nar-
rowest sphere, the omnipotence of her resources."
The temperature, the humidity, the degree of
motion in the air, modify these crystallized fig-
ures. Flakes that fall at the same time generally
have the same shape ; but, when there is an in-
terval between the falls, a new variety is found
each time.

FLOWERS UNDER THE SNOW.

In years when the snow has remained long
upon the ground, the watercourses are more
abundant, and the harvests more certain. Win-
ters at the North without snow are calamities

FLOWEKS UNDER THE SNOW. 79

equalled only by springs at the South without
rain. Snow acts as a covering, or screen, which,
in sheltering the soil, prevents it from being
thoroughly congealed, by the radiation of all its
caloric into space, in clear, cold nights ; and then,
when the thaw conies, it fully saturates the
ground.

Between the eternal snows that cover the tops
of the Pyrenees and the Alps, and the slopes at
their foot, where the vine flourishes, there is a
region in which the snow melts at different sea-
sons, according to its elevation ; but, in all places,
even at great heights, where it remains for six or
eight months, when it does disappear it leaves the
soil covered with rich herbage that vegetated un-
der its shelter, and that offers an abundant pas-
ture to the flocks and herds. The green sward
thus strengthened is immediately enamelled with
a multitude of lovely flowers that had budded be-
neath the snow. The attempt had often been
made, but in vain, to acclimate these Alpine
plants in our gardens, when a florist conceived
the idea, which seemed odd enough at first, to
place them, during the winter, between the orange
and pomegranate trees in his hot-house. The
hardy plants brought from a rude region, where
the climate is similar to that of Siberia, and where

80 METEORS AMD METEORIC PHENOMENA.

the mercury sinks to 30° below zero, were per-
fectly preserved by the process. This was be-
cause they found in the hot-house the conditions
provided for them by the thick covering of snow
that shielded them in their natural haunts. By
its diminutive conducting power, the covering in
question shelters them from cold, and, above all,
from those abrupt changes of temperature that
are so injurious to frail organizations. By anal-
ogy we may infer how grain is protected by the
snow in the furrows of our fields.

GLACIERS AND RIVERS.

An admirable arrangement in the glaciers of
the Alps has been made apparent by a series of
observations, carefully pursued for several years
consecutively, in regard to the mean depth of
water in the rivers flowing from them, in each
month of the year. " Since much less rain falls
in summer than in other seasons," says Jean
Reynaud, " and since it evaporates again almost
immediately, all the small streams diminish in
volume, and some are even dried up altogether ;
thus, at last, the main watercourses do not re-
ceive from their tributaries sufficient aliment to
sustain them. But Nature has arranged a pecu-
liar class of tributaries for rivers important enough

GLACIERS AND RIVERS. 81

to require such special provision, and these yield
them all the more in proportion as their ordinary
resources diminish, and vice versa. These are the
streamlets that flow from the glaciers ; and the
immensity of the process required to supply them
will be comprehended at once, when we reflect
that they must necessarily be raised from the
mountains above the clouds, in order to take their
rise where they do. None but regions lifted up
to those prodigious elevations would be in a posi-
tion to accumulate such a quantity of snow and
ice, and to retain enough of it during the summer,
allowing it to melt, little by little. Thus, the
hotter the summer and the more extreme the
drought in the watercourses of the plains, only the
more rapidly and copiously will the deposits of
ice heaped up at the fountain-head be made to
melt. Consequently the mountain-brooks will be
the fullest at the very moment when the others
will be most completely exhausted. On the other
hand, in spring and autumn, when the abundance
of rain causes the streamlets of the valley and the
plain to swell in every direction, and tends to
raise the rivers above their regular beds, the
glaciers, receiving less heat, feed the rills that
flow from them less lavishly, and an actual dry-
ness results, so far as they are concerned, which

82 METEORS AND METEORIC PHENOMENA.

counterbalances the humidity of the regions lower
down. The general result is, that the rivers which
are subject solely to the influence of the glaciers
are full in summer and shallow in winter ; while
those which are cut off from all connection with
the reservoirs of the high regions, and are depend-
ent upon the rains alone, have the most water dur-
ing the cold season and the least in the hot months.
Finally, those that have the aid of both the
glaciers and the rain, at different times, along
with ordinary tributaries and such as flow from
the high mountains, have, other things being
equal, a more even and steady supply of water
than the rest."

HAIL.

Hail is a shower of globules of ice, the size of
which usually varies from that of a pea to that of
a hickory-nut, but sometimes attains the dimen-
sions of an egg, and even of an ordinary apple.
It has been remarked that there is nearly always
a little accretion of spongy snow in the centre of
hailstones. This is their only opaque portion ;
the concentric layers that surround it have all the
transparency of ordinary ice. The nucleus and
its coverings therefore do not seem to be formed
in the same manner* Sometimes there fall heavy

HAIL.

hailstones with a snowy centre which are com-
posed of rings or layers alternately transparent
and opaque. The fine soft hail seen in autumn
and winter particularly, the surface of which
looks as though powdered with flour, is usually
called sleet. It is, properly speaking, a kind of
middle formation between hail and snow.

Yolta relates that one night in the month of
August, 1707, he picked up, during a storm that
burst over the town of Como, several hailstones
that weighed nearly ten ounces. Darwin men-
tions a tempest on the pampas of South America,
where the icy fragments that fell were so heavy
as to kill large animals.

We have just spoken of a hailstorm that hap-
pened during the night. This is a very rare oc-
currence, for it is usually during the hottest hours
of the day in summer that hail forms. The
clouds that contain it seem to have great depth,
and are distinguished from other storm-clouds by
their ashy color. Their edges have numerous
jagged indentations, and circular movements are
sometimes remarked in them. Hail usually pre-
cedes storms of rain, and sometimes accompanies
them ; but it scarcely ever follows them, especial-
ly when the rains have lasted for any time. In
the tropics, hailstorms have been noticed only on

84 METEORS AND METEORIC PHENOMENA.

the lofty mountains. None falls in the plains.
It is more particularly frequent in the temperate
zone, and then becomes more and more rare as
we advance toward the polar regions.

In most cases, the phenomenon of hail has a
local character. It is very frequent at the outlet
of the deep valleys of the Alps and upon the
lower acclivities that separate them from the
plains. The low lands of Borgo-franco, near the
Yal d'Aosta, are scourged by it every year; At
Clermont, at the foot of the Puy-de-D6me, hail
falls very often, while on the heights, half a
league distant, but one fall of hail has been re-
corded in the last twenty-three years! Some-
times there are great storms during which hail
falls over a vast extent of territory, but these are
fortunately rare.

The formation of hail has been more easily
explained since the discovery by aeronauts of very
cold atmospheric layers (the thermometer mark-
ing 40°) at heights comparatively limited, and
that too in midsummer. These layers, as we have
already said, are filled with fine needles of ice,
which, when packed together, may form the nu-
cleus of the hailstones, upon which the vapors
solidify themselves in other layers. The exist-
ence of whirlwinds, arising from the collision of

HAIL. 85

opposite currents — chiefly equatorial and polar —
explains the suspension and even the ascension,
by a spiral movement, of the hailstones that form.
Leaves and twigs, torn from trees by a tempest,
have been seen to fall at a distance, covered with
a coating of ice.

The currents originated by these whirlwinds
are generally in opposite electrical conditions be-
fore they become mingled. Hence it is remarked
that it rarely hails without thunder being heard,
and that during such a fall the electricity de-
veloped varies not only in degree but in kind.

Some years ago, rows of long poles were
planted in the fields in France to serve as hail-
rodsy or protectors against the hail. They were
intended to modify the electrical conditions of the
atmosphere ; but the system was found to fall
short of the purpose, and Arago, in arguing
against it in one of his learned " Notices," advises
farmers to give more of their attention to mutual
cooperative associations, until science shall have
discovered some better defence against the rav-
ages of the storm.

CHAPTEE IY.

PHENOMENA OF THE GLACISES.

Meteorology of the Glaciers.— Their Formation.— The Grindelwald and
Furca Glaciers. — Amphitheatres.— Neves.— Moraines.— Movements
of the Glaciers.— Primitive Glaciers.— Polar Glaciers.— Variations of
the Seasons and Climate.

METEOROLOGY OF THE GLACIERS. THEIR FORMATION.

WE have already spoken of the favorable in-
fluence of glaciers upon the mean height of the
watercourses during each season. In a remarka-
ble note appended to the work on " Meteorology,"
by Kaemtz, M. Chas. Martins, one of the most
learned professors of the day, summarily examines
the influence of temperature and aqueous meteors
on these solid rivers that, issuing from the region
of external snow, descend slowly into the plains,
in the midst of forests and cultivated fields.

" If we examine the phenomena presented by
the glaciers," says M. Chas. Martins, " in a pure-
ly meteorological point of view, we shall see that

METEOEOLOGT OF THE GLACIERS. 87

it is not too rash to maintain that a time will
come when we shall be enabled to judge the
modifications of the atmosphere by those of the
glaciers, and vice versa. But in order thus to
establish in a positive manner the link that unites
the meteorology and the physical exterior of the
globe, it is desirable to make a long series of
meteorological observations in the vicinity of the
glaciers, so as to bring the two kinds of phenome-
na into direct rapport"

Before making known some of the modifica-
tions indicated in this passage, we must pause for
a brief space to consider the formation of the
glaciers. This is the point of departure recom-
mended by M. Martins for the desired observa-
tions.

When, in summer, the clouds disperse, after
the tempests of rain that fall in the plains, the
summits of the mountains are seen whitened with
newly-fallen snow, which melts very quickly in
the sun, but remains on the highest peaks, in the
region of eternal snows, as low down as a certain
limit that varies according to the country and the
exposure. This limit, when traced upon an ex-
tended chain of mountains, appears to be almost
horizontal ; but, at certain points in the depth of
the valleys, the glaciers are seen descending in long

88 METEORS AND METEORIC PHENOMENA.

white trains to the plain. M. George Altmann,
in his " Treatise on the Icy Mountains of Switzer-
land," has given the following description of the
Grindelwald glacier, so often explored by natural-
ists:

THE GRINDELWALD AND FURCA GLACIERS.

" The village of Grindelwald is situated in a
long and narrow gorge of the mountains. From,
that point we begin to get a glimpse of the
glacier, but, in order to see it in its full extent,
we must go higher up. Then one of the finest
spectacles that can be imagined is revealed. It
is a sea of ice, or an immense expanse of frozen
water, which descends into the valley along the
slope of a lofty mountain. From this frozen
reservoir starts a prodigious mass of pyramids
heaped together, forming a kind of curtain that
occupies the whole breadth of the valley, an ex-
panse of about eight hundred yards, and is bor-
dered on both sides by lofty mountains, covered
with verdure and a forest of pines up to a certain
height. This accumulation of pyramidal forms
looks like a sea agitated by the winds, the waves
of which have been suddenly congealed by the
frost ; or, rather, one beholds an amphitheatre
formed by an immense assemblage of icy hillocks

THE GKINDELWALD AND FUKCA GLACIERS. 89

of a bluish color, and each of them from thirty to
forty feet in height. The point of view is of
marvellous beauty. Nothing is comparable to it,
especially when, in summer, the sun darts its rays
upon this group of glittering pyramids. Then the
entire glacier begins to smoke, and glows with a
brightness that dazzles the eyes."

We will add to this description the account of
the Furca glacier given by Coxe in his " Letters
on Switzerland":

" After long efforts and a toilsome march over
immense stretches of snow and ice that came in
our way, with precipices and torrents constantly
beneath our feet, we reached the upper part of the
valley by an extremely steep ascent. The great
number of forked and irregular masses of rock
which, accumulated around this valley, stud the
summit of the eminence, have, it is said, originated
the name now given it of the Forks or Furca.
The region in which we then were, appeared
more frightful and desolate than even the most
desert parts of Saint Gothard. Below us, it is
true, the mountains were clad in rich verdure, and
bestrewn with fragrant flowers ; but vegetation did
not reach to the height where we were. The
most savage sterility surrounded us, and near by
there rose a fearful accumulation of ice, from which

90 METEORS AND METEORIC PHENOMENA.

there descended a cataract that, rolling toward the
Yalais, is no doubt one of the sources of the
Rhone. This glacier was on our left and a little
above us, and never did any mass of objects, how-
ever grand or terrible, present to us a combina-
tion of beauty at once so terrifying and so sub-
lime.

" From that point we descended a mass of
broken rocks which, in every direction, bristle the
ridges of a long line of precipices. I then felt
sufficiently fatigued to require rest and refresh-
ment. We seated ourselves on the banks of a
very limpid streamlet which flowed briskly down
the mountain, the latter being so steep that our
little repast had to be propped to prevent it from
rolling away from us. Before us the Furca gla-
cier lay extended in all its beauty. It is an im-
mense mass of ice that spreads out, in the form of
an amphitheatre, between two heaps of rocks more
jagged, if possible, than any that we saw in the
neighboring mountains. This amphitheatre en-
tirely fills the precipice that separates them, and ,
rises gradually from their base to a short distance
from their summits. The sun, which darted its
rays perpendicularly upon the glacier, gave it the
brightness and transparency of crystal, while the
shadows of its vast fragments, admirably colored,

CIRCLES, NEVE, ETC. 91

intersected its dazzling whiteness with all the
varying tints of a truly celestial blue. Terrible
cracking noises, indicative of new crevices form-
ing in the glacier, were heard several times ; and
the Rhone, pouring along at its feet in the form
of a torrent, mingled its continuous roaring with
the din. It is in a great measure to the accumu-
lation of ice that I have just described that the
river owes its existence."

CIRCLES. NEVE. MORAINES.

Ramond, the naturalist^ the intrepid explorer
of the Alps and Pyrenees, and the translator of
Coxe's book, has added to his translation some ex-
cellent observations on the glaciers, and has been
one of the first to point out a part of the causes
that concur in their formation and determine
their progress. Before him, Haller, De Saussure,
and De Luc, had already established a number of
important facts. But it is to more recent re-
searches that we owe the explanation of most of
the phenomena connected with the nature and
movement of glaciers.

" Snow accumulates around the high peaks in
deep depressions known as amphitheatres. It is
in descending from these amphitheatres toward

the valleys that the snow is transformed, under
5

92 METEORS AND METEOKIO PHENOMENA.

the influence of the sun and nocturnal frosts, tc
small grains of transparent ice, and that this
granulated mass, called neve in Switzerland, be-
comes converted, by pressure and successive con-
gelations, to a moving mass of ice, sometimes
white and filled with bubbles of air, and some-
times more compact and skyey blue."

Such is the origin of the glaciers, which their
own weight causes to advance slowly in the direc-
tion of the declivities. Huge crevices are pro-
duced during this movement, and the water that
drips down into them when the snow melts, accel-
erates it by hollowing out cavities in the lower-
most parts of the mass. Besides, when the water
thus contained in the glacier dilates by a new
congealment, the entire mass increases in volume,
and extends in the direction where it finds the
least resistance, that is to say, from the higher
point to the lower. This continual progression
of the glaciers has been proved by incontestable
facts.

A bed of pebbles and sand being interposed
between the bottom of the glacier and the rock,
the result is, that the action of the masses of ice
in movement polishes the surface over which they
descend, and makes creases and furrows running
in the same direction. This effect has been well

CIRCLES, NEVE, ETC. 93

ascertained, not only in the ice-caverns that are
sometimes found at the extremities of the glaciers,
but also on the rocks that border them. These
rocks, rounded by the ponderous effort of the
mass that presses them, often assume a particular
aspect, which renders them distinguishable at a
distance, wherever a glacier has worn itself a bed.
Some of these, seen far away, look like flocks of
sheep, and for this resemblance De Saussure the
naturalist has invented the term rockes mouton-
nees, or " sheep-shaped rocks."

Another order of phenomena demands our
attention. As M. Martins has well said, in his
" Eesearches on the Glacier Period," " The Alps
are immense ruins. Every thing conspires for
their destruction ; all the elements seem to have
combined to bring down their proud summits.
The masses of snow that weigh upon them so
heavily in winter, the rain that filters in be-
tween their beds in summer, the sudden action
of torrents, the less abrupt but still more power-
ful operation of chemical affinities, wear away,
separate, and decompose the hardest rocks. Their
debris falls from the upper heights, into the am-
phitheatres occupied by the glaciers, in the form
of considerable land-slides, accompanied by a ter-
rific uproar and immense clouds of dust. Even

94: METEOES AND METEOEIC PHENOMENA.

in midsummer I have seen avalanches of stone
precipitate themselves from the uppermost sum-
mits of the Schreckhorn, and form upon the hith-
erto spotless snow a long black streak, made up
of enormous blocks and a countless number of
smaller fragments."

These blocks, some of which measure from
ten to twenty yards in thickness, either way, are
borne along by the glacier, and consequently
form long streaks, which skirt across its borders,
or accumulate in transversal lines at its extremi-
ties. These streaks of debris^ left by the ava-
lanches and land-slides, have received the name
of moraines.

MOVEMENTS OF THE GLAOIEES. PEIMTnVE GLACIEES.

By these interesting observations, not only
has the movement of the glaciers been circum-
stantially proved, but we have been enabled to
demonstrate their ancient extent by the furrows
grooved in the rock by the primitive glaciers, and
by following in the valleys the traces of their lat-
eral and transversal moraines.

Thus, the glaciers of Mont Blanc once extended
from Chamouni to Geneva. On the eastern slope
of Jura there are found isolated bowlders, or wan-
dering Hocks, so called, of granite, which can have

MOVEMENTS OF THE GLACIERS. 95

come from no other source than the mountains of
Switzerland, the Jura chain being composed of
calcareous stone. The immense glacier, which
transported these blocks to the height of a thou-
sand yards above the level of the sea, extended
across the plain that is comprised between the
Alps and the Jura. It was, in Martins's opinion,
the principal glacier of Switzerland, the others,
which are also indicated by the plainest traces,
being but its tributaries.

To Jean Perraudin, a chamois-hunter, the
first idea of this cataclysm is due. A learned
geologist, M. de Charpentier, to whom he had
communicated the result of his observations,
made it the subject of persevering research, and
obtained the most incontestable proof of the
grand phenomenon which had been pointed out
to him. The study of the glacier period is thus
connected with the revolutions of which our
globe has been the theatre. Numerous scientific
works, among which we must mention in the first
rank those of M. Agassiz, have indicated in the
two hemispheres the same traces of antediluvian
glaciers, extending over the wide plains that sur-
round our mountain-ranges.

Professor Tyndall, in his fine work on " The
Glaciers of the Alps," attributes the present con-

96 METEORS AND METEOEIO PHENOMENA.

formation of the Alpine chain, in a great measure,
to the movements of those prodigious masses of
ice which have traced immense furrows in the
rock, hollowed out the valleys to great depths as
they passed, and by this very action prepared their
partial destruction. In fine, Mr. Tyndall explains
that the currents of warm air that rise from the
valleys toward the heights, have a temperature
the more elevated and a force the greater the
deeper the valley is. Hence it results that the
glacier grows smaller as it sinks lower, and that
it reaches limits at last which it cannot pass.
This equilibrium between the thaws of summer
and the increase and advance of winter appears to
be established at the present day, and, with some
rare exceptions, we know the mean limit beyond
which the ice never goes.

We find among the Pyrenees, the Yosges, the
mountains of Scotland, and the principal ranges
on the globe, the same traces of an immense de-
velopment of primitive glaciers. We are igno-
rant, as yet, of the cause of this phenomenon, super-
induced, as it was, no doubt, by meteorological
conditions very different from those now ex-
isting, but which persevering observation of the
disturbances taking place under our eyes will
perhaps enable us to discover. Thus, Professor

MOVEMENTS OF THE GLACIERS. 97

Frankland, of the Royal Institution of London,
lias recently shown that the limit of the eternal
snows is higher in the interior of continents than
in the vicinity of seas. It may be readily under-
stood, in fact, how an abundant production of
watery vapor is one of the principal causes of the
formation of glaciers, the vapor becoming snow
and ice in the high regions of the atmosphere.
But the abundance of aqueous meteors is also in
correspondence, as we have seen, with the temper-
ature, so that it is impossible to admit the exist-
ence of the immense glaciers of which the traces
and deeply-worn channels are found on all sides,
at the very period when the mean temperature of
the globe was above the present temperature.
The chains of mountains, which had just then ap-
peared, had not yet been encroached upon by the
slow but potent action of the different agents of
destruction that excavate and reduce them, and
those primitive chains presented a vast surface
for the accumulation of snow and ice, the forma-
tion of which was favored by the more frequent
vicinity of great lakes and interior seas, such as
the ancient sea of Sahara, indicated by Charles
Lyell in his " Principles of Geology."

Maury, in his excellent researches on the geo-
logical part performed by the winds, has put in

98 METEORS AND METEORIC PHENOMENA.

the way of completion some important discoveries
regarding the relations that subsist between the
quantity of moisture set in circulation by the at-
mosphere and the configuration of the seas and
continents. The action of the great aerial cur-
rents, as well as that of the great oceanic cur-
rents, varies with the circumstances that favor
or obstruct it, and these variations are in close re-
lation to the distribution of heat upon the globe.
It is to these causes, which are still incessantly at
work, that Mr. Lyell attributes also " the principal
revolutions of the meteorological condition of the
atmosphere at different geological epochs."

The conflict of the elements, subjected, accord
ing to the region, to the influence of heat and
cold, necessarily produced convulsions correspond-
ing in extent and intensity to the greater or less
power of these influences, and left on the surface
of the globe the deep traces that science discov-
ers there to-day. " The phenomena," says M.
Martins, " have remained the same ; but, instead
of those gigantic manifestations characteristic of
the geological epochs preceding our own, they re-
strict themselves to the limits of action which
have been imposed upon them by the equilibrium
of the period of repose that the coming of man
has inaugurated on the earth."

POLAR GLAGIEKS. 99

POLAR GLACIERS.

The limit of the eternal snows descends lower
in passing from the equator to the poles, from the
glaciers of the Cordilleras that cover the volca-
noes of Peru, to those of Spitzbergen, which
come down to the edge of the sea, and fill up the
bottom of the bays. These last-mentioned gla-
ciers present a remarkable peculiarity. Upon the
western coast of the island, bathed by one of
the branches of the great lukewarm current of
the Atlantic — the Gulf Stream — the sea thaws
during the summer, and melts the lower part of
the glaciers, which, continually advancing, at
length pass beyond the shore. The parts which
are no longer supported below are then seen de-
taching themselves and forming the field-ice that
is met with in such quantities in the Arctic Ocean.
Madame Leonie d'Aunet has described this phe-
nomenon, as follows, in her interesting " Yoyage
to Spitzbergen" :

" During my sleep the thaw had commenced,
and the physiognomy of the day had changed as
though by a miracle. A spectacle of the utmost
turbulence and agitation had succeeded to the
motionless solitude of the evening before. A
flotilla of islands of ice surrounded the corvette,

100 METEOBS AND METEORIC PHENOMENA.

and covered the bay as far as the eye could see.
The ices of the pole, which no dust has ever soiled,
as pure now as on the first day of the creation,
are tinged with the most vivid colors. One would
say the rocks were precious stones. One sees the
sparkle of the diamond, and the dazzling hues ol
the sapphire and the emerald, blended in an un
known and marvellous substance. These floating
islets, incessantly undermined by the sea, change
their forms at every instant. By an abrupt
movement their base becomes their summit; a
needle changes to a mushroom; a column imi-
tates an immense table; a tower is transformed
to a staircase. And all this is so rapid and un-
expected that one cannot help thinking that some
supernatural power must control the sudden
transformations. At all events, from the first
moment, I fancied that I saw before me the ruins
of a fairy city suddenly destroyed by a supe-
rior power, and condemned to disappear without
leaving a single vestige where it had stood. I
saw fragments of architecture in every style and
of every period dashing together around me —
belfries, columns, minarets, ogives, pyramids,
turrets, cupolas, crenellated battlements, volutes,
arcades, pediments, colossal masses of masonry,
carvings as delicate as those that encircle the

VARIATIONS OF THE SEASONS AND CLIMATES. 101

slender pillars of our cathedrals — all there con-
founded and commingled in one common dis-
aster. The palette could not reproduce, and mere
description cannot convey, an idea of this strange
and wondrous combination.

" This place, where every thing is cold and
inert, is represented as being wrapped in a pro-
found and gloomy silence, is it not? Well, a
totally different conception of it must be formed.
Nothing could reproduce the tremendous tumult
of a day of thaw at Spitzbergen.

" The sea, studded with sharp pinnacles of ice,
plashes noisily ; the tall masses bristling along the
coast slide down, break from the rest, and plunge
into the gulf with a terrific crash ; the mountains
crack and split apart ; the waves dash furiously
against the granite capes ; the islands of ice as
they break up make a succession of crackling
sounds like discharges of musketry, and the gust
tosses whirling clouds of snow on high with
hoarse roarings. It is terrible ! It is magnificent !
One seems to hear the choirs of the abyss of the
old world intoning the prelude to a new chaos."

VARIATIONS OF THE SEASONS AND OF CLIMATES.

We have seen how the melting of the glaciers
maintains the volume of the rivers during the

102 METEORS AND METEOEIO PHENOMENA.

summer-time, and thus, in keeping up the water-
courses, contributes to refresh and fertilize our
fields. The floating ices of the pole, which then
descend toward our latitudes, also moderate the
heat of our summers by the influence of winds
and currents. Sometimes, even, as a learned
meteorologist, M. Renou, has remarked, a cold
summer like that of 1816 may be the conse-
quence of a great breaking up of the polar ices.

The regions adjacent to the two poles may be
considered as immense glaciers, resting upon
rocks of greater or less elevation, and sometimes
upon lofty mountains, the summits of which pierce
the snow. Two volcanoes, the Erebus and the Ter-
ror, were discovered in 1841 by Sir James Ross,
during his expedition to the Antarctic regions.
The Erebus, which is about 12,000 feet in height,
and covered with snow to the crater, threw out
dense volumes of smoke at intervals.

A knowledge of the causes that, in these
regions, determines the periodical increase or
diminution of the ice, would be of great interest
for the general meteorology of the globe. These
variations seem to be connected with a variation
of seasons dependent upon the periodicity of the
solar spots, as M. Renou indicates, or on the
movements of the earth, in its orbit, as hinted by

VARIATIONS OF THE SEASONS AND CLIMATES. 103

Jean Reynaud, when referring to the secular va-
riation of climates in his u Terre et Ciel." But a
long series of observations on the glaciers of both
hemispheres would be necessary, in order to solve
these important questions with any certainty.

Already numerous discoveries, due to the in-
trepid zeal, the devotion, and the scientific skill of
the great explorers who penetrated the icy soli-
tudes of the pole, and the burning deserts of the
equator, or climbed the perilous summits of our
highest mountains, have opened new horizons to
investigation. In the vast totality of meteoric
phenomena, until then so confused, we have,
through their aid, seen a few simple laws stand
forth that shall hereafter serve to guide us in
studying the perturbations of the atmosphere and
the modifications that they lead to on the surface
of the globe.

CHAPTER Y.

THUNDER-STORMS.

LuminouE Phenomena.— The Fires of St. Elmo.— Thunder-storms among
the Mountains.— The Forms of Lightning.— Globular Thunder-bolts.—
Thunder.— Singular Effects of Lightning.— Lightuing-rods.— Geogra-
phy of Thunder-storms.— Influence of the Soil.— Volcanic Storms.—
Action of Thunder-storms upon the Subterranean Waters.— Utility
of Thunder-storms.

LUMINOUS PHENOMENA. FERES OF ST. ELMO.

THE air during a thunder-storm is some-
times so highly charged with electricity, that it
becomes visible in the midst of the obscurity
by a vivid light resting on all surrounding bodies,
and particularly upon the water. Mention is
made of luminous rains, during which the ground
seemed to be on fire. More than once travellers
have been seized with alarm on seeing their wet
clothes all aglow on stormy nights. A curious
narrative addressed by M. Allemand, a physician
of Fleurier, near Neufch&tel, to Professor Piotet,
as mentioned in the Bibliotheque Universelle of
Geneva, sets forth a case of this kind :

LUMINOUS PHENOMENA. 105

" On the third of May last, I was called to
Motiers about ten o'clock in the evening, and was
surprised, so to speak, as I was leaving the vil-
lage, by a storm that was quickly followed by a
very heavy rain. Although provided with a
walking-stick umbrella, I thought I had better
close it, as the thunder grew more frequent and
severe, and I even held the upper end, which, as
you may know, forms a metallic point, in my
hand ; the point is blunt indeed, yet it might at-
tract the lightning. Ere long, the night, which
was excessively dark already, became more so
with torrents of rain, and it was only by the help
of the vivid and frequent flashes of lightning,
that I was able to pursue my way. Thus moving
along through the most violent tempest that can
be imagined in our part of the country, I sudden-
ly noticed a light that appeared to come from
above, and, at once raising my eyes, I remarked
that it was the brim of my hat that seemed to be
illuminated. Thinking that it was real fire, and
without taking time to reflect, I suddenly passed
my hand along the luminous edge, expecting to
extinguish it. But, to my great surprise, it only
shone the brighter, and this gave me a confused
idea that I had been mistaken as to the charac-
ter of the light. My hand was full of water that

106 METEORS AND METEOEIC PHENOMENA.

flowed from my hat, and, in making a motion to
shake it off, I saw it shine like a piece of polished
metal reflecting a bright light.

" Hereupon, to the sensations that I had ex-
perienced until then, succeeded such emotion as
caused me to utter half aloud an exclamation of
fear. I was then about one hundred paces from
the Chaux farm, that is to say, about ten minutes'
walk from Fleurier, and fifteen or twenty from
Motiers. I deliberated for a moment whether I
should seek shelter in the farm-house, or continue
on my way ; but, at last, some scientific reasoning
in my own mind, and profound reliance upon the
Supreme Author of the formidable apparatus by
which I was surrounded, decided me to push on.
Having been enabled to fill my hand unharmed
with the electric water that gleamed along the
brim of my hat, I felt emboldened to repeat the
experiment — although, after all, I did so the sec-
ond time with a sort of fear — and ascertain
whether this phosphorescent light had no odor,
and whether it produced neither a crackling
sound nor sparkles of flame. But I saw only the
beautiful light I had remarked in the first in-
stance, which did not rise from my hand at the
moment when I opened it, but seemed to be ap-
plied to its surface like a shining varnish. This

LUMINOUS PHENOMENA. 107

light lasted only for an instant. Continuing on
my way, with my gaze almost constantly riveted
upon the brilliant halo that bordered my hat, I saw
another vivid light on the surface of the smooth
handle of my umbrella, at the spot where the me-
tallic plate is usually found on which the name of
the owner is engraved. My first movement was
to pass my thumb over the place, in order to ex-
tinguish this new fire, which had become as per-
plexing to me as the other. The same phenom-
enon ensued ; that is to say, the part rubbing be-
came quite as luminous as the part rubbed. I
then felt afraid of the umbrella, the metallic
mounting of which was continually before my
mind, and I threw it down. The thunder-claps
increased, although the electric concussion seemed
to be, and was, indeed, at some distance from me.
Once relieved of my umbrella, I endeavored to
rub the rim of my beaver briskly with the
sleeve of my coat, but this had no other effect
than to make the crown of light more vivid, and
I arrived with it at Motiers. I attribute its ces-
sation to the proximity of the tall poplars that
border the road near that village."

These effects are explained by the influence of
the storm-clouds in the upper region of the at-
mosphere. The latter attract, at the surface of

108 METEOES AND METEORIC PHENOMENA.

the soil, an electricity contrary to that with
which they are charged. Frequently the pencils
of rays that one sees at the extremity of the
points placed on an electric machine in operation,
appear in enlarged dimensions upon all kinds of
salient objects, metallic bars and uprights, the
spires of belfries, and the masts and yard-arms of
ships. Those brilliant little flames, which sailors
call the fires of /St. Elmo, indicate the abundant
emission of the terrestrial fluid, neutralizing the
fluid of the clouds. "We shall cite, in addition to
the above, only the following facts, as Arago
gives them :

" On January 14, 1824, just after the close
of a storm, M. Maxadorf , happening to look at a
wagon loaded with straw, in the middle of a
field near Gothen, over which hung a huge
black cloud, observed that every stalk stood out
straight and seemed on fire. Even the whip of
the driver threw off a vivid light. The phenom-
enon disappeared as soon as the wind had swept
away the black cloud, but it had lasted ten min-
utes.

" On the 8th of May, 1831, after sunset, some
officers were walking bareheaded, during a storm,
on the terrace of the Bab-Azoun fort in Algiers,
when each of the party remarked with surprise,

STOKMS AMONG THE MOUNTAINS. 109

as he looked at his neighbor, that there were little
pencils of light at the ends of his hair. When
these officers raised their hands, similar luminous
plumes formed at the ends of their fingers."

STORMS AMONG THE MOUNTAINS.

A Swiss engineer, M. Buchwalder, was en-
gaged in geodesic operations on the summit of
Mont Sentis, at a height of seven thousand five
hundred feet above the level of the sea, when he
was caught in a violent storm. " Heavy clouds,"
he says, " coming from the west, enveloped the
mountain. Yery soon a violent wind announced
a tempest ; thunder was heard in the distance, and
the hail fell in such abundance that, in a few min-
utes, it covered Mont Sentis with a sheet of ice.
"We took refuge in our tent, and I carefully closed
all the openings so as to leave no hold to the
wind. For a few moments, the storm seemed to
abate, but it was only an interval of silence, a res-
pite, during which a terrible crisis was in prepara-
tion. In fine, at eight o'clock in the morning, the
thunder was heard again, but much nearer and
more violent, and it continued thus, for hours to-
gether, without cessation. Tired of my long im-
prisonment under the tent, I went outside, to note
the condition of the sky and measure the depth

110 METEORS AND METEORIC PHENOMENA,

of the hail that had fallen. Scarcely had I taken
a few steps in the open air, ere the thunder burst
over my head with such fury that I deemed it
prudent to regain the shelter of my tent, and my
aid followed my example. In order to diminish
the danger of being struck by the lightning, we
lay down side by side upon some planks. At this
moment a cloud, as dense and black as night, en-
veloped Sentis. The rain and hail fell in tor-
rents ; the wind blew with fury, and the flashes
of lightning succeeded each other incessantly,
crossing and recrossing in every direction, and
surrounded us with a lurid light like the reflec-
tion of a fire. The crashes of thunder, rebounding
from the precipitous sides of the mountain, leaped
from echo to echo with such vehemence that we
could scarcely hear ourselves speak. The sound
was a sharp, rending noise ; a quivering crash, as
though the heavens had fallen in, and a dull pro-
longed roar, all in one. At length, the fierceness
of the storm became so terrible that my companion
could not restrain an emotion of alarm, and asked
me if we were not in imminent danger of losing
our lives. I endeavored to reassure him by men-
tioning the fact that Arago and Biot, during their
observations in Spain, were surprised by a simi-
lar tempest. The lightning had struck their tent,

STORMS AMONG THE MOUNTAINS. Ill

but had glanced off from the cloth without hurt-
ing them.

" Hardly had I told him this, ere I heard a cry
of distress : l O my God ! ' — and at the same in-
stant I saw a ball of fire flash from the feet to the
head of my companion, and felt a violent shock in
my left leg. Our tent, also, was torn asunder in the
middle with a terrific detonation. I turned toward
my companion ; the unfortunate man had been
struck by the thunder-bolt ! In the light yielded
by the tearing open of the tent, I saw the left side
of his face dotted with red and brown spots caused
by the electric fluid. His hair, his eyelashes, and
his eyebrows, were singed and burnt ; his lips and
nostrils were a livid blue ; his breast heaved for
a moment, and then the sound of his breathing
ceased. I was suffering horribly myself; but,
forgetting my own mishap in my anxiety to aid
my companion, who, I saw, was dying, I called
him aloud, I shook him, but he made no response.
His right eye, which was wide open, brilliant and
full of intelligent meaning, seemed turned upon
me to implore my assistance, but the left eye re-
mained closed, and, on parting the lids, I saw
that it was dull and leaden. I still thought that
there was a remnant of life in him, but only for a
moment ; three times I tried to close that right

112 METEORS AND METEORIC PHENOMENA.

eye, which was still gazing fixedly at me, and
three times it opened again, with all the look of
life. I then placed my hand over his heart ; it
no longer beat. At last, my grief put an end to
this distressing examination. My own left leg
was paralyzed, and I felt an acutely painful
shivering in it, accompanied by an extraordinary
agitation or boiling of the blood. A convulsive
tremor ran through my whole body; a general
stifling sensation half choked me, and my heart
beat in the most tumultuously irregular manner.
Was I to perish like my hapless companion ?
Thank God, however, I managed to reach the
nearest village, after extreme exertion. Subse-
quently I discovered that my instruments had
been struck by the lightning, for every metallic
article that the tent contained when the thunder-
bolt fell, bore traces of the passage of the fluid.
The points, edges, and most delicate parts, were
softened and melted."

THE FORMS OF LIGHTNING. GLOBULAR LIGHTNING.

Sometimes the clouds, during a storm, seem
to give out a continual emission of electricity, for
they remain luminous a long time, as Rozier, the
physiologist, observed, during a storm of great
intensity that he witnessed in the environs of

THE FOKMS OF LIGHTNING. 113

Beziers. " Little by little," he says, " a luminous
point that made its appearance in the midst of
dense clouds, assumed breadth and volume. It
then, by imperceptible degrees, formed a zone, or
phosphorescent band, which revealed itself to my
eyes as about three feet in height ; it at last sub-
tended an angle of sixty degrees. Above this first
zone, another formed of about the same height,
but of not more than thirty degrees' measurement.
An open space of about the same extent separated
them. In both these belts were noticed irregular-
ities similar to those seen on the edges of the
heavy clouds that are the forerunners of a storm.
These edges were not equally luminous, although
the centre of the belts presented a uniform bright-
ness. "While they were advancing toward the
east, the lightning darted three different times
from the end of the lower belt, but without
any appreciable detonation." This phenomenon
lasted for a quarter of an hour, and was dispelled
by a violent gust from the southward, that carried
the storm to a distance.

These intermittent discharges of electricity
have very varied forms, and traverse the atmos-
phere with astonishing velocity. Wheatstone has
demonstrated that the most brilliant and ex-
tended lightnings — sometimes from fifteen to

114: METEOES AND METEORIC PHENOMENA.

eighteen miles in length — do not last the thou-
sandth part of a second. Some consist of very
delicate shafts of light, with very sharply-defined
borders, describing zigzag lines in space, and
sometimes dividing into several branches. Most
usually they are white, and sometimes, but rarely,
purplish, violet-hued, or bluish.

Others extend, on the contrary, over a wide
surface, and have neither the whiteness nor the
brilliant illumination of those before mentioned.
Their hue is often a very vivid red. "These
lightnings," says Arago, " appear, sometimes, to
illuminate only the outlines of the clouds from
which they emanate. Sometimes, too, their viv-
id light embraces the entire superficial extent
of those same clouds, and, moreover, seems to
issue from the interior of them. One might say
with truth that the clouds open. Such is the
popular expression, and I should search in vain
for others to depict the same phenomenon more
accurately."

The first kind of lightning is much more rare
than the second. In ordinary storms, hundreds of
the latter appear for every one instance of linear,
or, more especially, of forked lighting. "We will
here quote the description of a remarkable storm
observed by M. Liais during his sojourn in Brazil.

THE FORMS OF LIGHTNING. 115

Although it was the 30th of January, the
thermometer marked thirty-three degrees. " Dur-
ing the night, the wind came up very feebly from
the southwest ; in the morning the air was pure,
and a burning sun fell upon the soil, still damp
with the rain of the preceding days. In the after-
noon there were seen some cirri. Toward even-
ing other clouds, cumulus and cumulo-stratus
formed, and, at sunset, the sky was almost covered.

" At seven o'clock, flashes of lightning were
seen in the east, and, at ten minutes past seven,
the storm had acquired all its intensity. At that
time, zigzag lightnings were darting forth contin-
ually, at least one-third of them forked. These
flashes were white, and very vivid. Sometimes,
they seemed to tend slightly toward a bluish
tinge, and, at others, were of an orange hue.
They did not form interrupted zigzags, as they do
in many storms, but rather broken lines, and,
moreover, each of these lines was sinuous. These
lightnings did not end in points, but generally
presented a slightly-rounded form at the ex-
tremity where they terminated. Although these
flashes had great velocity, it seemed to me that
their development, and the manner of their prop-
agation, could be followed with greater facility

than in ordinary storms. Two flashes were very
6

116 METEORS AND METEOEIC PHENOMENA.

rarely seen at the same time, and their emission
had a certain regularity.

" The most of these flashes were unaccom-
panied by any noise. From time to time we
could hear a slight rumbling in the distance, but,
owing to its frequency, without being able to dis-
tinguish to what flash it belonged. Many of
them seemed to issue from a sort of very small
cumulus, situated but a little distance above the
horizon, and to propagate themselves with an
apparent ascensional movement. Others seemed
to issue from the upper bed of clouds, with an
apparent inverse movement. The storm was not
accompanied by rain. Only at the beginning a
few large drops had fallen. The upper cloud,
upon which the lightnings shot out in relief, did
not cover the entire face of the sky, and a few
stars could be seen.

" I pass on now to the most singular part of
the phenomenon. Besides the two-forked light-
nings and those with three or four offshoots, which
were also very frequent, not a moment went by
without our seeing also what might be termed
arborescent or tree-shaped lightning. These were
flashes that divided themselves into several prin-
cipal branches, which in their turn split off into
a multitude of smaller boughs, that again pre-

THE FOKMS OF LIGHTNING. 117

sented the same sinuosities, and the same round-
ed endings noticed in the other flashes. There was
no other means of counting these branches than
by reproducing immediately on paper the impres-
sion made on the retina of the eye. One of these
flashes, that I had remarked particularly, and that
had appeared to propagate itself as it descended,
divided, at first into two branches, which subdi-
vided in their turn, in such manner as to form
fifteen branches in all. Another was of radiating
form, and one arborescent, that is to say, its prop-
agation was in every direction, but starting from
a common centre.

" The tempest seemed to continue motionless.
At the end of about ten minutes, the frequency
of the flashes diminished ; at a quarter past eight,
they ceased, and the clouds soon dispersed. The
zodiacal light was seen in the west and the east,
below the milky way, spanning the entire sky.
It may be well to mention that on the preceding
evening the phosphorescence of the sea was ex-
traordinary, and such as I had never seen it be-
fore. On the evening of the storm, on the con-
trary, it had resumed its usual appearance under
the tropics."

In another storm, M. Liais again noticed the
extremely curving shape of the ends of the arbo-

118 METEORS AND METEORIC PHENOMENA.

rescent flashes, and a still more marked tendency
to terminate in balls of fire. Three times these
balls broke off, leaving a train of light behind
them, like a bolide, and traversing an arc on the
sky of thirteen degrees in half a second. We have
seen the origin of a third kind of lightning, which
the physiologists call globular lightning, without
being able, up to the present time, either to ex-
plain it or to imitate it, as they do with ordinary
lightning. It is entirely analogous, excepting in
dimensions, to the sparks of an electric battery.
These globes of fire, which are sometimes as large
as a bomb, descend to the ground with a motion
slow enough to enable the observer to note their
shape. Their color varies from dead white to
vivid red. In advancing along the soil, they
seem to keep aloof from the surface of objects
and emit no heat. They are sometimes seen to
stop for an instant, then to advance again, and
then rebound, like an elastic ball, or divide into
several smaller globes. Sometimes, at the end of
their course, a plume seems to issue from them,
and then they explode with a noise like that of a
cannon, hurling zigzag lightnings on all sides of
them, that produce the most fearful ravages.

THUNDER. 119

THUNDER. SINGULAR EFFECTS OF LIGHTNING-STROKE.

The sound caused by a single flash of light-
ning sometimes lasts without interruption as much
as forty-five seconds. Although it is true that all
the beds of air lying along the course of the im-
mense electric spark are shaken, so to speak, at
the same time, the sound developed at each point
reaches the observer only by successive concus-
sions, and the difference in distance produces the
variations noticed in the violence of the thunder,
its rolling reverberations, and its sudden crashes,
repeated again and again by the echoes. The
discharges that take place between a cloud and
any terrestrial object are the most severe.

We cannot account for some of the phenom-
ena of transporting power revealed by lightning,
unless we call in some other force than electricity.
It was beyond all doubt the power of steam alone,
eliminated on its passage, which could, for instance,
lift a wall weighing twenty-six tons, and carry it
in one mass a distance of many yards. Repeat-
edly, the roofs of huge edifices have been swept
off as though by the explosion of a mine.

In passing through bodies, the lightning very
rapidly raises their temperature. Metallic con-
ductors nearly a third of an inch thick have been

120 METEORS AND METEORIC PHENOMENA.

melted by it, and, when of less dimensions, have
been completely volatilized. Bell- wires are found
incrusted in tiny drops in the floor, or shot in fine
dust over the walls.

Travellers often see the surface-beds of rock
on the tops of mountains vitrified by the lightning.
When it penetrates beds of sand it forms tubes
of melted and adhering quartz, sometimes thirty
and forty feet in length, which have received the
name si fulgurites. The following fact is cited
by M. Jamin : " On the 17th of July, 1823, the
lightning struck a birch-tree, near the village of
Rauschen, on the borders of the Baltic. The in-
habitants, who hurried to the spot, saw two deep,
narrow holes close to the tree, and one of them
seemed warm to the touch, notwithstanding the
rain. Professor Hagen, of Koenigsberg, caused
the ground around the holes to be dug away with
great care. The warm one presented nothing
peculiar ; the other also, for the depth of a foot or
so, offered nothing remarkable, but a little lower
down commenced a vitrified tube. The fragility
of the tube, however, did not admit of its being
taken out in pieces over an inch or two in length.
The inside glassy lining was very shiny, of a
pearl-gray color, and studded with black points
along its entire extent."

LIGHTNING-RODS. 121

Masses of iron and steel traversed by lightning
become magnetic, and numerous observations show
that, on board of vessels that have been struck, the
compasses have been made to deviate from their
normal direction. Trees, which are excellent con-
ductors, because of their moisture, are often struck.
In such cases, where the burning of the tree has
not ensued, the trunk is seen to be dried up and
divided into long strips. Inside of houses, all
combustible bodies take fire on the passage of
lightning through them.

LIGHTNING-BODS.

The identity of electricity and lightning was
proved by Franklin. " In order to verify a con-
jecture he had formed on the subject," says
Mignet, one of his biographers, " he undertook
to draw electric fluid from the clouds. The first
means that occurred to him was to erect point-
ed iron rods that might attract it This device
not seeming practical to him, upon mature reflec-
tion, because he could not find any place suffi-
ciently high, he conceived another. He constructed
a kite of two pieces of stick, covered with a silk
handkerchief. The longer stick he terminated
with an iron point at its upper extremity. He
then tied to the kite a hempen cord ending with

122 METEORS AND METEORIC PHENOMENA.

a silk one. Where the hempen cord, which was
a conductor, and the silken one, which was not,
joined, he fastened a key, so that the electricity
might accumulate there and throw off sparks an-
nouncing its presence. With his apparatus thus
prepared, Franklin went out to the fields one day
during a storm. His kite, carefully secured by its
string, which was in its turn made fast to the silk
cord, was given to the air, while Franklin himself
stood aloof and watched it with anxiety. For
some time he saw nothing, and was afraid that he
had been mistaken ; but, all at once, the string at
both ends stiffened and the key became charged.
It was the electricity descending. Franklin hast-
ened to the spot where he had secured the string
at the lower end, presented his finger to the key,
and received a smart shock that might have killed
him, but, as it was, only filled him with delight."
By the invention of the lightning-rod, Frank-
lin proposed to neutralize the effects of thunder-
clouds by furnishing them with an electricity the
opposite of their own. He protected buildings
with long metallic rods, terminating in sharp
points at the top, and communicating with the
ground. Along these the terrestrial electricity
escapes toward the overhanging cloud, and neu-
tralizes it more or less rapidly. Sometimes, dur-

LIGHTNING-RODS. 123

ing the night, tall plumes of electric light are seen
shining on these points. It may happen that the
cloud is not sufficiently discharged, and the light-
ning may strike between it and the edifice. How-
ever, in that case, it falls upon the stem of the rod,
which is connected with the ground by an isolated
conductor.

The efficacy of lightning-rods is fully demon-
strated by statistics. Mr. Snow Harris reports,
for instance, that in Devonshire six churches with
tall steeples having been struck, one of them
only, that was protected by a lightning-rod, suf-
fered no damage. The Church of St. Mark at
Venice, the Valentino palace at Turin, the
tower of Sienna, all in cities where the lightning
causes frequent damage, have likewise been pre-
served by lightning-rods.

"We well remember the terrible thunder-storm
that burst over the city of Strasburg on the 14th
of August, 1833, about four o'clock in the after-
noon. The tower of the cathedral was struck
three times in the space of a quarter of an hour.
At the last stroke, the whole pile appeared to be
in flames for some seconds. In many places, the
lead, the copper, the iron, and even the mortar
were found to be melted, or vitrified. Fragments
of metal had soldered themselves to the bells, and

124: METEOES AND METEORIC PHENOMENA.

it was found difficult to detach them. Yery large
masses of stone fell in the neighboring streets.
In the next year, one of the turrets was cut in two
by the lightning, and it was at last decided to
put up lightning-rods on the spire and other parts
of the edifice. Since that time, it has been re-
marked, as a matter of fact, that it has been
struck by harmless discharges only, which fell on
the rods and followed the conductors into the
ground, without the least deviation. Moreover,
thunder-storms appear to have become less fre-
quent and less intense over Strasburg.

Let us, also, mention the following instance,
where, as Arago phrases it, " Mature was caught
in the act." " On the 21st of May, 1831, during
a very violent thunder-storm, the ship Caledonia
was under sail in Plymouth Bay. From the
town, the lightning could be seen darting toward
the water, at but a short distance from the vessel.
It fell also on the shore and there caused several
accidents. Surrounded, as it were, by these fall-
ing thunder-bolts, the Caledonia, protected by her
lightning-rods, yet escaped all harm and sailed
along as safely as though the sky had been clear."

Extreme care, as recommended by all our
learned associations, but too often neglected, is
required in the construction and keeping of the

LIGHTNING-BODS. 125

lightning-rod. It is of special importaDce that
the point should be of metal that will not oxidize,
and that the conductor should be united with iron
ligatures to all the large metallic pieces of the
structure, and be in perfect communication with
the ground. In damp soil, the electric flow and
dispersion are very easy, but the iron rusts and is
quickly worn out. In a dry soil, there would be
insulation, and great mishaps might be appre-
hended. The conductor in such a case must be
made to run into a pit full of slacked cinders ; coal,
when it has been red heated, being an excellent
conductor, while it has the additional good prop-
erty of not attacking iron. When there is a nat-
ural sheet of water in the vicinity, the conductor
might be led into it, and provided with numer-
ous branching pieces where it does so. A reser-
voir or cistern cannot be considered in the same
light as a well or pit, properly speaking, since, the
stone blocks and the cement that line its bot-
tom and sides yield but difficult passage to elec-
tricity ; there is no free dispersion, and a violent
concussion might ensue.

The difference in the conducting power of
different soils, and of the bodies placed there,
should, as well as their form, direct the choice of
localities in which one is the least exposed to be

126 METEORS AND METEORIC PHENOMENA.

struck by lightning. According to the considera-
tions presented in the foregoing pages, care must
be taken not to get under trees, or to go too
near to large metallic masses, or very high build-
ings.

Men and animals have been killed beneath
a thunder-cloud, without being struck directly
by lightning. This phenomenon, called the re-
turn-stroke by physiologists, is explained by the
influence of a very extensive electrified cloud,
discharged at one of its extremities by lightning.
If, at that moment, then, bodies, beneath the
other extremity being powerfully influenced, re-
turn suddenly to their natural condition, they
experience a very violent shock.

THE GEOGRAPHY OF THUNDER-STORMS.

Humboldt found vitrified surfaces, caused by
lightning, on the summit of the mountain of
Toluca, at the height of 13,860 feet above the
level of the sea. This fact does not prove that
thunder-clouds can attain that elevation, for there
are cases on record where lightning has struck the
tops of mountains, starting from their base. On
the other hand, again, the inhabitants of Chamouni
affirm that thunder-storms have passed over the
summit of Mont Bknc, which is 14,430 feet high.

THE GEOGRAPHY OF THTJNDER-STOKMS. 127

Arago gives 228, and even 91 feet as the lower-
most limit, which, according to exact measure-
ment, can be assigned to thunder-storms.

The principal elements in the geographical
distribution of thunder-storms are in relation with
the distribution of rain. Kearly all the rain of
the tropical regions falls from thunder-clouds, and
under the equatorial belt one hears the rumbling
of thunder almost continuously. At Calcutta
sixty thunder-storms per annum are counted, and
among them forty-five occur during the southwest
monsoon, that is to say, from April to September.
There are none from November to January, or
during the northeast monsoon. We have already
referred to the exceptional case of Peru, where
the inhabitants have never heard thunder.

In the zone of tropical calms, thunder-storms
are frequent ; less so, however, than under the
equator. The example of Europe may give an
idea of the state of things in the middle latitudes.
In southern Spain there are the same number of
thunder-storms, say, from five to ten, as in Eng-
land and Scandinavia. Italy, the Adriatic Sea, and
Greece, present the maximum of the European
ratio of thunder-storms. Janina and Rome have
forty-five and forty respectively per annum.
Among the Alps about thirty are counted. In

128 METEORS AND METEOKIO PHENOMENA.

France and Germany there are from fifteen to
twenty. In the latter country, however, certain
localities, such as Munster, Braunsberg, etc., which
are exposed to frequent thunder-storms, are re-
markable exceptions to this rule. It is in the
Adriatic, and. upon the western coasts of Europe,
that the winter thunder-storms are most frequent.
As we advance toward the east, they become less
numerous, and, beyond the frontiers of Germany,
only summer thunder-storms are noticed.

In the high latitudes, thunder-storms are ex-
tremely rare. Sometimes as long a period as six
years will pass without thunder being heard in
Greenland. Farther on we shall state how the
thunder-storm is replaced in those regions by the
splendid phenomena of the aurora borealis.

In the tropics, thunder-storms are always
caused by ascending atmospheric currents, and
the same is the case with the summer thunder-
storms of the temperate zones. They take place
every afternoon, when the arrangement of the
country is favorable to them. Above some of the
lakes of Switzerland there thus daily appears a
small cloud that moves over and fixes itself on
the slope of a neighboring mountain, and then
bursts with a terrific concussion. We have no-
ticed this periodical formation of thunder-storms,

THE GEOGRAPHY OF THUNDEK-STOEMS. 129

toward the close of summer, in the bays of Naples
and Tunis.

The thunder-storms of the temperate zone
usually accompany the heavy rains that result
from the meeting of the equatorial and the polar
currents. There then ensues a struggle between
the two winds that often lasts for several days,
and the result of which determines the state of
the weather. With the south winds, the air be-
comes heavy, warm, and damp, and dense clouds
ascend along the horizon. But suddenly the
northern gust sweeps down, accompanied with
electric explosions. The fluctuations of these
currents occasion several consecutive thunder-
storms, which exhibit no periodicity, and are of
very variable duration. Should the polar wind
prevail, all the vapors dissolve in rain, or are
borne off to a distance, and the sky clears up
again. Upon other occasions, it is the north
wind .that rules at the outset, with clear, dry, and
cold weather, which the arrival of the south wind
changes. This current is indicated in the high
latitudes by the cirrus, which rapidly grows more
dense, changes to cumulus, and covers the sky with
a thick veil of clouds, whence the lightning soon
begins to play. When the north wind yields, the
thunder-storm winds up with mild weather and

130 METEORS AND -METEORIC PHENOMENA.

those long rains that are so powerful a source of
fertility in the temperate zones.

INFLUENCE OF THE SOIL. VOLCANIC THUNDER-
STORMS.

According to some meteorologists, the nature
of the ground may contribute to the frequency of
thunder-storms. "In the department of May-
enne " (in France), says M. Blavier, a mining-
engineer, " there exist masses of diorite (a species
of rock in which loadstone is sometimes found),
which contain a notable proportion of iron, and
affect the needle of the compass. We were as-
sured that in certain parishes, such as Niort, for
instance, the most threatening thunder-clouds
would be seen to disperse as they drew near, or
to turn aside in certain directions. We think that
the conducting force of several considerable masses
of diorite will explain this phenomenon." The
savant Yicat reports the following observation,
made at Grondone, a village situated among the
Apennines, near a very rich iron-mine, that rises
in the form of an isolated peak. " Nearly every
day, in the months of July and August, an electric
cloud is seen forming above this region. The
cloud, growing larger by insensible degrees, re-
mains for some hours suspended over the mine,

INFLUENCE OF THE SOIL. 131

and then, in bursting, discharges itself toward the
peak, which is almost entirely metallic. The
miners," adds Yicat, " instructed by experience,
judge when it is time to quit the spot. They, at
the right moment, retire some distance, and then
return to their work after the explosion. I have
frequently seen the great cloud of Grondone form
about noon, and keep together until four or five
o'clock, and then, after a few claps, give way to a
small thunder-storm."

"We find the following curious passage in a
recent description of the caves and grottoes of Nor-
way : " A promontory of the Lyse-Fiord contains
a cavern really terrible, on account of the meteoro-
logical phenomena of which it is the scene. It is
well known that there are no rocky cliffs of more
sinister aspect than those of the Lyse-Fiord. It is
toward the fifty-ninth degree of latitude, at a short
distance to the eastward of the port of Stavanger,
that this arm of the sea opens. It is a prodigious
ditch, twenty-five miles or so in length, shut in
between two walls of sharp-pointed, perpendicular
rocks of the average height of more than half a
mile. No doubt the first mariner who navigated
the still, black waters of this chasm, must have
proceeded with a certain feeling of horror, asking
himself at every turn if he was not about to see

132 METEOES AND METEOEIC PHENOMENA.

some frightful old Norse deity start up before him.
Even now it is not without a shudder that one
penetrates this sea-defile, in which the ancients
would have recognized the entrance to Hades.

" When the southwest wind blows rudely, and
plunges by violent gusts into the vast chasm of
the Lyse-Fiord, a strange meteoric phenomenon
adds to the terrible majesty of the scene. Fifteen
hundred feet above the level of the sea, and at
two-thirds of the height of the wall that rises to
the southward of the entrance to the gulf, there
is seen a flash of lightning leaping, from time to
time, from the black rock, spreading, then con-
tracting, then expanding, and shrinking again,
and dispersing in luminous fringes before it
reaches the northern wall. This broad tongue of
fire advances, whirling round and round as it
goes, and it is to this rotary movement that the
apparent expansions and contractions of the light-
ning are due. E-apid detonations are heard with
an increasing power before the live flame leaps
from the rock ; a violent clap of thunder accom-
panies it, and reverberates in prolonged echoes
through this narrow corridor of the sea. One
would think that some battery, hidden behind
the cliff, was cannonading some invisible casemate
in the opposite wall."

EFFECT OF THUNDER-STORMS. 133

During volcanic eruptions, the clouds that
issue from the craters emit numerous flashes of
lightning. These clouds are composed of smoke
and vapor, mingled with ashes, and often of ashes
alone. In 1631, an immense column of smoke
rose from Vesuvius, and was borne for a distance
of more than one hundred and twenty miles.
During its passage it threw off shafts of lightning,
accompanied with thunder, that killed several
persons. In another eruption, the cloud, which
was extremely black and composed of impalpable
ashes, got as far as the town of Tarentum, where
the lightning set fire to a number of buildings.
These volcanic thunder-storms have also taken
place at sea. In 1811, when the island of Sabrina
emerged from the waters in the vicinity of the
Azores, the columns of dust and ashes that rose
from it were furrowed with lightning of extraor-
dinary vividness, according to the statement of the
ship-captain who witnessed the phenomenon.

THE EFFECT OF THUNDER-STORMS ON SUBTERRANEAN
WATERS.

Arago speaks of modifications that have some-
times taken place in underground waters during
stormy weather, in which thunder and lightning
play a part ; of springs that become troubled and

134: METEORS AND METEORIC PHENOMENA.

overflow, even after a great drought ; of deep wells
heard boiling and bubbling noisily ; of fountains
leaping from the rock with sensibly augmented
projectile force. Yallisneri has remarked that
the salsae and solfatarae, or volcanic salt and sul-
phur fields, in the vicinity of Modena, announce
thunder-storms by a sort of ebullition, and by
noises resembling thunder.

" Historians and meteorologists," says Arago,
"mention local inundations the effects of which
seemed to go far beyond what the small quantity
of rain issuing from the clouds, and falling with-
in a certain radius, could have led any one to
fear." It has rarely happened that, upon such oc-
casions, immense masses of water have not been
seen rising from the bowels of the earth, for a
greater or less period of time, from openings until
then unknown, or that a violent thunder-storm
has not been the precursor of the phenomenon
and probably its most immediate cause. Such,
for instance, were in every particular the circum-
stances of the inundation that in July, 1688,
almost utterly destroyed the villages of Kettlevel
and Starbottom in Yorkshire, England. During
the storm an immense chasm formed in the adj ac-
cent mountain, and, according to eye-witnesses,
the mass of water that gushed from it contrib-

EFFECT OF THTJNDER-STOKMS. 135

uted, as much as the rain, to the ravages that
ensued.

In October, 1755, according to Beccaria, a
sudden inundation produced great destruction in
most of the valleys of Piedmont. The river Po
overflowed, and the disaster was preceded by hor-
rible thunder, orrendi tuoni, says the learned Ital-
ian. Everybody agreed that the principal cause
of the inundation was the immense volume of
water which, during the storm, suddenly issued
through new openings from underground among
the mountains.

These local fractures of the solid crust of the
globe would have nothing very extraordinary
about them, were it proven that, in stormy
weather, the water has a tendency to seek the
clouds, and that this tendency manifests itself by
abrupt outbursts from below. This is precisely
the conclusion to be drawn from observations
made on board the packet-ship New York in
182Y. While the storm raged around the vessel
in question, the sea was in a continual ebullition
of such a nature as to convey the idea of subter-
ranean volcanoes. Especial note was taken of
" three columns of water which leaped high into
the air, then fell back, then leaped up again, and

once more subsided."

7

136 METEORS AND METEORIC PHENOMENA.

THE USEFULNESS OF THUNDER-STORMS.

Science teaches us to appreciate the beneficent
effects of the thunder-storm, the appearance of
which was once considered a sign of celestial dis-
pleasure. The explosions of thunder and light-
ning produce a profound modification in the con-
stituent elements of the atmosphere. The gases,
which are held merely in a state of simple mixture
in the absence of the electric spark, are combined
by its agency in such manner as to form ne"w sub-
stances, that are detected in various quantities in
rain-water. Under certain circumstances these
new combinations deposit the nitre that is found
on the surface of the soil in different countries.
The agricultural efficacy of that substance has
been known since the days of antiquity. Yirgil
mentions it in his "G-eorgics." Agricultural
writers recognize the value of other products of
the thunder-storm in helping vegetation. Each
electric discharge engenders in the atmosphere
fruitful principles of life, which are drawn into
the soil, where the roots of plants imbibe them,
and so communicate a fresh glow to their foliage
and flowers.

Thunder-storms, also, purify the atmosphere.
The passage of the lightning gives oxygen more

THE USEFULNESS OF TIIUNDEK-STOKMS. 137

active properties, and transforms it into ozone.
Although this gas is but little known, we are safe
in attributing to it a very energetic agency in
destroying miasma and neutralizing putridities
that, in spreading throughout the atmosphere,
render it unfit for respiration, and give rise to the
severest maladies. Ozone may be produced in the
laboratory by means of strong electric sparks. If
a bell glass be filled with it, spoiled meat and of-
fensive dirt placed under it soon lose their repul-
sive odor. All the imperceptible remains of or-
ganic substances are consumed on coming into
contact with the electrified air, and M. Schoen-
bein has established the fact that air, containing a
very small proportion of ozone, will disinfect an
equal volume of vitiated atmosphere.

According to recent researches, the hygienic
conditions of several regions appear to be in rela-
tion to the quantity of ozone in the atmosphere.
In many observatories, this quantity is daily as-
certained by means of the variations of color re-
vealed by a chemical substance. It is probable
that^irnportant laws will ultimately be developed
from a larger collection of facts.

After a thunder-storm, a peculiar odor, usually
spoken of as a smell of sulphur, or brimstone, is
diffused through the atmosphere. This smell is

138 METEORS AND METEORIC PHENOMENA.

due to the presence of ozone, and, farther on, we
shall see how it manifests itself in the haunts of
the great electric meteors that serve the purpose
of thunder-storms in the polar regions.

CHAPTER VI.

WHIRLWINDS.

Water-spouts.— Electric Whirlwinds.— Sand-storms.— Water-spouts at
Sea.— Water-spouts on Land.— Tornadoes.— Cyclones.— Hurricanes.

WATER-SPOUTS.

" AMONG the great meteors that come to trou-
ble the apparent order and harmony of Nature —
among the grand phenomena which carry terror
and desolation wherever they appear, there is one
which distinguishes itself from the rest by the
strange and gigantic forms it assumes, by the
outside forces that it seems to obey, by the un-
known and apparently contradictory laws that
appear to regulate it, and, to sum up, by the dis-
asters it occasions. These disasters themselves
are accompanied by peculiar circumstances, so re-
markable that the cause of them cannot be con-
founded with that of other meteors baleful to
humanity. This meteor, so extraordinary, so

140 METEORS AND METEORIC PHENOMENA.

menacing, and fortunately so rare in our lati-
tudes, is the one designated by the general expres-
sion of water-spout"

Such are the words of M. A. Peltier, in his
" Observations and Experimental Researches on
the Causes that concur in the Formation of
Water-spouts."

The least violent and least dangerous whirl-
winds are those that are produced by the meeting
of contrary winds, and have no other cause than
the mechanical impulsion of the forces set in mo-
tion during great atmospheric disturbances. Such
whirlwinds often form in mountainous countries,
where the wind buries itself in the gorges, blows
in varying directions, and is sometimes abruptly
interrupted by obstacles that turn it aside.

" I have often witnessed these phenomena in
the Alps," says Kaemtz, " but will content my-
self with relating the following fact: A very
strong south wind was blowing over the summit
of the Righi, and the clouds that passed above my
head were sweeping in the same direction. The
north wind was blowing toward Zurich, and as-
cending along the northern slope of the mountain.
"When it reached the summit, light vapors formed
and seemed to seek a passage over the crest, but,
the south wind throwing them back, they ascended

WATEK-SPOUTS. 141

toward the north, at an angle of forty-five de-
grees, and disappeared at the top. The struggle
of these two contrary winds lasted several hours.
A great number of whirlwinds formed at the
point where the two winds met, and travellers,
who usually feel but little interest in meteoric phe-
nomena, were struck by this singular spectacle."

The terrible whirlwinds that are met with
chiefly in the tropics, or accompany great thunder-
storms, often spring up in the midst of a calm,
and are probably produced by the most formidable
forces of electricity. The clouds, according to
Peltier, are the source of this power, when, after
a rapid evaporation in calm, warm weather, they
have retained the electricity that was in the va-
pors, and that, most usually, is dispersed through
the damp atmosphere into the soil. When the
clouds, thus charged with electric fluid, and often
accumulated in enormous masses, chance to com-
bine their forces with the perturbations of the at-
mosphere, they act with those that are peculiar to
them, and add powerful influences of attraction
and repulsion to the violent shocks of the air. All
the observations that have been made relative to
water-spouts, tend to prove that they are the
result of a transformation of these electric clouds.

Before the appearance of these water-spouts,

142 METEOES AND METEORIC PHENOMENA.

which are much more frequent at sea than upon
the land, black, stormy clouds collect, and the
lowermost one in the series is seen descending in
the shape of a reversed cone, the point of which
approaches the ground or the water in a greater
or less degree. Beneath this descending cloud,
the waters appear to be in a state of ebullition,
and the vapor that issues from them rises like
smoke. On land, light bodies, such as dust, etc.,
are carried upward and form whirlwinds. Some-
times the point of the cone touches the sea, and
there hollows out a grand circular depression, as
though a violent current of air issued from it.
Less frequently, the waters are lifted up in the
form of a column, or an ascending cone. In the
midst of the vapor-clouds that surround the lower
part of the water-spout, sheaves of water gush
upward, and fall again on the outside. "This
mass of water," says Peltier, " raised in the form
of a whirling, boiling smoke ; these ascending and
descending jets, seen from a distance, have the
appearance of a thicket, or a hedge, such as Eng-
lish navigators are accustomed to call e the bush.' J:
"Water-spouts nearly always emit a deafening
noise, a strange, whizzing sound, which increases
or diminishes according to the greater or less
dampness of the ground over which they pass.

ELECTRICAL WHIRLWINDS. 143

They are frequently accompanied by whirlwinds
in the air, lightning, thunder, hail, and rain.

ELECTRICAL WHIRLWINDS. SAND-STORMS.

There have been dry, whirling storms, or
whirlwinds, that have caused great destruction,
without having been preceded by any gathering of
opaque clouds. Peltier admits that the invisible
vapors collect in transparent clouds that may be
charged with electricity, like opaque clouds, and
reproduce the same phenomena.

On the great deserts, during a dead calm, and
under a blazing sun, the sand sometimes rises in
the midst of electric whirlwinds, that remind one
of a water-spout. Piddington, in his "Law of
Storms," relates a very interesting summary of
observations made in Hindostan by Dr. P. Bad-
dely:

" My observations extended from the warm
season of 1847, the period of my first coming to
Lahore, until 1850 ; here is the result :

"Sand-storms are caused by spiral columns
of electric fluid passing from the atmosphere to
the ground. They have a forward movement, a
rotary movement, like the whirling storms at sea,
and a special spiral movement from top to bottom.
It is probable that in an extensive sand-storm,

144: METEORS AMD METEORIC PHENOMENA.

most of these columns move together in the same
direction, and that, while the tempest lasts,
sudden and numerous gusts take place at in-
tervals, in which the electric tension is at its
maximum.

" The same phenomena are to be seen in every
case of sand-storm ; from those that are but a few
inches in diameter, to those that have fifty miles
and more of extent, the phenomena are identical.

" It is a curious fact that some of the smallest
sand-storms that are seen occasionally in the
great arid plains of this country (India) and Af-
ghanistan, above the Bolan Pass, and which are
called ' devils ' in vulgar parlance, are stationary
for a while, that is to say, for an hour or more,
and, during all this time, the sand, or dust, and
other light bodies from the ground, keep up their
whirling movement in the air. In other cases,
small sand-storms advance slowly, and when they
are numerous they move usually in the same di-
rection. Frequently, birds, such as kites and vul-
tures, soar above these heights, and evidently
follow the direction of the column, as though it
gave them pleasure. I think that the phenomena
associated with sand-storms are identical with
those that are presented by water-spouts, in white
squalls at sea, and in tornadoes of every descrip-

SAND-STOKMS. 14:5

tion ; and that they arise from the same cause,
that is to say, from movable columns of electri-
city.

" In 184Y, at Lahore, desirous of satisfying
my mind in regard to the nature of sand-storms,
I placed in the open air, on the roof of my house,
a copper wire insulated upon a bamboo. I led one
end of the wire into my room, and put it in com-
munication with an electrometer with a golden
plate and a wire connecting with the ground. A
day or two afterward, during the passage of a
small sand-storm, I had the pleasure of seeing the
electric fluid passing from one wire to the other
in vivid sparks, and powerfully affecting the elec-
trometer. The fact was, henceforth, explained ;
and since that time I have, by the same means,
taken note of at least sixty sand-storms of differ-
ent dimensions. All of them presented the same
phenomena.

" I have observed that, usually, toward the
termination of a storm of this kind, the rain falls
suddenly, and that, instantaneously, the current
of electricity ceases or greatly diminishes ; when
it continues, it would seem that it does so only
in cases where the storm is of considerable power,
and lasts for some time afterward."

The author then gives an account of his ineth-

146 METEORS AND METEORIC PHENOMENA.

od of observing these phenomena, and afterward
goes on with his description of whirlwinds :

" The sky is clear ; not a breath of air is stir-
ring ; but see, presently there is a bank of clouds
far down the horizon, and you are surprised that
you did not notice them before : a few seconds go
by, and the mass of cloud has covered half the
celestial hemisphere ; there is no time to lose ; it
is a sand-storm, and every one rushes hurriedly
in-doors to escape being caught in it.

" The electric fluid continues to descend inces-
santly along the conducting wire, while the storm
lasts. The sparks are often more than an inch in
length, and emit a dull, crackling sound. Its in-
tensity varies with the force of the storm, and, as
I said above, is strongest during the sudden gusts.

" One of these storms, which took place last
year in the month of August, seemed to come .from
the direction of Lica, on the Indus, to the west of
Lahore. An officer on the march, twenty miles
distant from Lica, was suddenly enveloped in it.
His tent was swept away, and he was thrown
down and nearly suffocated by the sand. At
Lica the whirlwind cracked the walls of a solid
brick building, in which the same officer had re-
cently lodged, and tore up some trees in the en-
virons by the roots.

WATER-SPOUTS AT SEA. 147

" I have repeatedly tried to discover the kind
of electricity developed, and have found that it is
not invariably the same. Sometimes it appears
to be positive, and at others negative. It changes
during the storms."

WATER-SPOUTS AT SEA.

The extraordinary effects produced by these
tornadoes, their strange destructive power, and the
singularity of their forms, prepare our minds to
comprehend how they were regarded in old times
as evil spirits, who, in this prodigious disguise, re-
joiced in desolating the face of the country and
spreading terror far and near. Superstition, even
now, sometimes attributes a sort of personality to
these destructive meteors, whose monstrous aspect
and capricious movements vividly strike the im-
agination. Then the latter, by the aid of ignorance,
may give birth to the most absurd fantasies, hap-
pily dispelled in our time with ease, by the light
of science and reason.

Peltier has reproduced the following account
of a whirlwind seen by Dr. Leymerie on the 2d
of September, 1804, on board the Le VoMtour :

" This vessel was coming from Cayenne, steer-
ing for the coast of Africa, and was not far from
the river Gambia, when the whirlwind formed.

148 METEORS AND METEORIC PHENOMENA.

Before its appearance there was a dead calm.
The preceding days had been very warm, and,
since morning, the sky had become covered with
heavy clouds. The cutter was in pursuit of a
British slaver, when, all at once, those on board of
her saw a column of water, about three hundred
feet in height, rise from the sea to meet an-
other column (of vapor), descending from the bed
of clouds overhead. At this instant, the calm
was broken and the storm began to rage furious-
ly. The column in question was not composed
of water in its liquid state, but in the condition
of very dense vapor, as had been frequently re-
marked. This column was luminous throughout
its whole diameter, and had a slightly yellowish,
or tawny, phosphorescent appearance. The sea
itself was blazing with light, and the vessel left
behind her a long wake of fire. The storm lasted
for fourteen hours, and caused many disasters in
those waters ! "

Navigators frequently have recourse to their
guns, in order to break the water-spouts. "When
the ball passes through them, they are sometimes
seen to separate into two parts, which most usual-
ly reunite very quickly. Sometimes, on the other
hand, the ball simply dashes the water in jets on
each side of the column, without affecting it other-

WHIRLWINDS ON LAND. 149

wise in the least. "Water-spouts, as Peltier re-
marks, frequently offer a curious fact, which
would seem irreconcilable with the theory of
wind tornadoes being the cause of the phenome-
non. Many cone-like points start from the clouds
and soon combine in one and the same cylinder.
It is difficult to demonstrate that different torna-
does thus aggregate in a single shaft, while the
attractive forces of electricity may readily enough
determine this method of uniting. In the same
manner, the cloudy cone is seen dividing into
several spirals, which reunite and separate again,
a circumstance that sets aside the idea of an
impulsion received from the tornadoes of the
air.

WUmLWINDS ON LAND.

Let us now reproduce two accounts of water-
spouts on land, that will give an accurate idea of
this terrible meteor. The first was observed and
described by the learned meteorologist Professor
Grossmann :

" On the 25th of June, 1829, about two o'clock
in the afternoon, at a point a league below Treves,
east-northeast of Ruwer and Pfalzel, about twenty
degrees above the horizon, a phenomenon showed
itself that struck a great number of men at work

150 METEORS AND METEORIC PHENOMENA.

out of doors with amazement, and kept them in
uneasy suspense for half an hour.

" A fall of rain had taken place and the sky had
remained covered with clouds, when, all at once,
from the middle of a black cloud that rose in the
east-northeast, a luminous mass began to move
in the opposite direction and rend it violently.
The cloud speedily assumed, at the top, the form
of a chimney, from which escaped a whitish-gray
smoke, mingled occasionally with jets of flame, and
rising through several openings with as much
force as though, to use the expression of the look-
ers-on, it had been driven by so many bellows.

" The meteor had advanced over the vineyards
of Disburg and opposite to Ruwer, when, some
distance farther to the south, on the right bank of
the Moselle, and completely in contact with the
soil, another meteor suddenly appeared. It scat-
tered the heaps of charcoal piled up around a
tree, threw down a laborer at an adjacent lime-
kiln, and dashed across the Moselle with a terrific
concussion, as though a great many stones were
shaken together. The water leaped in a column
high into the air.

" Continuing to roll along with the same up-
roar, the meteor, still grazing the ground, darted
across the Pfalzel country, leaving everywhere be-

WHIEL WINDS ON LAND. 151

hind it the most evident traces of its zigzag route
in the grain-fields and vegetable-patches. Part
of the crops was totally destroyed, part was beaten
down and torn to pieces, and part whirled away
into the air.

" Many women fainted with terror as the me-
teor passed near them, and others, who were far-
ther off, hid themselves or fled, shrieking that the
6 fields were all on fire ! ' Two laborers, who had
climbed a tree, watched the meteor along its en-
tire course ; a third had even the bold idea to fol-
low it, which it was easy to do, at the ordinary
walking gait. At length, in one of its zigzag
movements, it suddenly enveloped him. He felt
himself at one moment violently jerked forward,
at another tossed up. He then bent down, bracing
himself strongly on the ground, with his working-
tools ; but he was, nevertheless, prostrated. The
tornado, however, left him, and passed on its way.
The man could recollect no particular impression
affecting his smell or taste, but merely a deafening
noise. He affirms that there were two currents of
air, the one rising obliquely, carrying up with it
the stalks and stems of the grain, along with other
light bodies, and the second operating in a con-
trary direction.

" The track that the meteor had opened for it-

152 METEORS AND METEORIC PHENOMENA.

self across the country was, according to different
statements, from ten to eighteen paces in breadth
and about twenty-five hundred paces in length.
Its shape was almost conical, and its color was,
at one moment, a grayish-white or yellow, at an-
other a dark-brown, but most of the time a fiery
red. The first meteor remained in the air above
the second, and followed a nearly parallel route,
going toward the north. For about eighteen
minutes it presented a large mass of whitish-gray
cloud, which repeatedly seemed to vomit name-
colored smoke, and, when seen at the distance of
about a mile and a half, had the form of a serpent
about one hundred and forty paces long, with its
head to the north-northeast and its tail in the
opposite quarter.

" In eight or ten minutes, the tail had already
changed its position by bending downward. Just
at the moment when it was about to touch the
head, the whole phenomenon disappeared, and
the lower meteor vanished at the same instant,
without any detonation from either of them, as an
eye-witness affirms ; but, with this, a strong smell
of sulphur spread over the whole country. Near-
ly at the same moment, a storm burst forth among
the woods situated to the north-northwest of the
place where the meteor had appeared, and was

THE TOENADO OF MONVILLE. 153

accompanied by a fall of extremely large hail-
stones.

" The sun was not seen during the whole of
this time, as most of the spectators declare, and
there was not a breath of wind.

" The upper meteor was seen from Cassel, Gut-
weiler, and other places, as also at Treves. It
seemed to descend from the heights of Hoch-
wald."

THE TOENADO OF MONVILLE.

The tornado of Monville and Malaunay pro-
duced still more fearful effects. The description,
incorporated in the Oomptes Rendus of the
French Academy of Sciences, has been summed
up by Professor Daguin, of Toulouse, as follows,
in his " Treatise of Physics " :

" On the 19th of August, 1845, a violent south
wind prevailed in the environs of Rouen. In
the afternoon, a gust from the southwest, driving
some very dark clouds before it, met the southern
current, and formed a strong whirlwind, with a
sidelong movement that tore up a hundred and
eighty bulky trees, twisting and wrenching nearly
all of them, and throwing down a drying-house
belonging to an adjacent factory. At the same mo-
ment, there was a heavy shower accompanied with

154: METEORS AND METEORIC PHENOMENA.

thunder and hail. However, there was no tornado
as yet, properly speaking ; but, after receding to a
distance and traversing some twenty-five miles,
the storm suddenly returned into the valley near
Malaunay and Monville, passing through a wood,
the trees in which it broke off close to the ground.
At that moment, an enormous cone, of sharply-de-
fined outline and as black as coal-smoke, was seen to
assume shape. The top of it was of a reddish-yel-
low, while it emitted flashes of lightning and a
heavy rumbling sound. In a few seconds, the tor-
nado hurled itself, with appalling velocity and by
zizag motion, through three considerable spin-
ning-mills in succession, crushing them and all the
working-people in them. The roofs were swept
off, and not one stone left on another. The looms
were twisted, the heavy pieces shattered, chiefly,
too, where there were ponderous masses of metal.
The trees in the vicinity were flung down in ev-
ery direction, riven and dried up for a length of
from six to twenty feet and more. While clear-
ing away the ruins, in the attempt to rescue the
unfortunate people buried beneath them, it was
noticed that the bricks were burning hot. Planks
were found completely charred, and cotton burned
and scorched, and many pieces of iron and steel
were magnetized. Some of the corpses showed

THE TOKNADO OF MONVTLLE. 155

traces of burning, and others had no visible cuts
or contusions, but seemed to have been killed by
lightning. Workmen who were hurled into the
surrounding fields, all agreed in saying that they
had seen vivid flashes and had noticed a strong
smell of sulphur. Persons who happened to be
on the adjacent heights, alleged that they saw the
factories wrapped in flames and smoke as the cloud
enveloped it. The breadth of the belt laid waste
by the tornado was seven hundred and fifteen feet
on the level of Malaunay, less than one and a
half miles from the point where its ravages
began, nine hundred and ninety-five feet in the
middle, and one hundred and ninety-five feet near
Cleres, where the cloud disappeared. The length
of the belt, as the bird flies, was about ten miles.
" One really very remarkable circumstance is,
that debris of all kinds, such as slate, glass,
planking, and pieces of wood- work, mingled with
cotton, fell near Dieppe, at a distance of from
fifteen to twenty-three miles from the scene of the
catastrophe. These various objects were beheld
in the air by several persons, who mistook them
for the leaves of trees, so high were they above
the ground. Among the scattered fragments
carried thus far, was a scantling more than a yard
long, five inches wide, and half an inch thick.

156 METEORS AND METEORIC PHENOMENA.

Happily, all such whirlwinds are not so destructive
as the one described."

When a thunder-storm changes to a whirlwind,
the sound of the thunder ceases at once. The
electric discharges are effected through the de-
pressed clouds, and the trees that stand in the
track of the meteor. These trees, when traversed
bj the electricity, are dried up in a moment, and
the whirl breaks them instead of tearing them up.
The enormous meteor of this kind that laid waste
the parish of Chatenay, on the 18th of June, 1839,
in this way destroyed the plantations of trees in
the valley lying "between the hills of Ecouen and
the eminence of Chatenay. "Fifteen hundred
feet of trees," says Peltier, " had evidently served
as conductors to masses of electricity, and to con-
tinual, incessant discharges of lightning. The
temperature, greatly increased by this flow of the
electric fluid, instantaneously vaporized all the
moisture in these vegetating conductors, and this
vaporization caused every one of them to split
lengthwise."

TORNADOES PROPER.

The hurricane - storms^ or cy clones , during
which the wind blows with extraordinary violence,
veering at a leap, more or less suddenly, from one

TORNADOES PROPER. 157

point of the horizon to the other, are also classed
among those terrific phenomena, the whirling
motion of which seems ascribable to an immense
electric action. All the descriptions that have
been given of them go to show that these meteors
are produced like those last described — Toy beds of
thunder-clouds.

The tornadoes of the western coast of Africa
are sometimes rectilinear gales of wind, like the
pamperos of South America, and the arched
squalls of the straits of Malacca, " which rise,"
says Horsburgh, in his " East India Sailing Direc-
tions," " with a black arch of clouds ascending
rapidly from the horizon to the zenith, and
scarcely giving time to take in sail." But, in
most cases, these tornadoes are veritable " cy-
clones in miniature," as Piddington correctly calls
them.

" On the approach of a tornado," says Hop-
kins, in his work on atmospheric disturbances, " a
dense mass of clouds gathers in the east and on the
horizon ; it is accompanied by frequent, dull, but
brief noises, that remind one of the growling of
some wild animal. This bank of clouds gradually
covers a part of the horizon, and extends from
there to the zenith ; but generally, beforehand, a

small, radiating arch, of well-defined outline, ap-
8

158 METEOES AND METEORIC PHENOMENA.

pears on the edge of the horizon, and continually
increases. Long before it reaches the ship, one
hears the whizzing of the wind, which produces
nearly as much noise as the roaring of the thunder
when it seems to rend the clouds apart with vio-
lence. The course of the gale is distinctly marked
by the line of foam that it raises."

The following description, given by Mr. Min-
graden in the Quarterly Journal of Science, 1837,
completes these observations : " When the torna-
do is approaching, it is remarked that the rain
seethes down in torrents, and that the flashes of
lightning part the clouds in such profusion that
they resemble continual discharges of electric
fluid. When, however, the squall has got within
half a mile of the ship, these electric appearances
cease altogether. The rain only continues the
same. When the tornado passes over the vessel,
there is a dull crackling distinctly heard in the
rigging. It is occasioned by the descent of the
electric fluid along the masts, the tips of which
serve to attract it ; and I have been told that, when
this phenomenon occurs at night, every part of
the rigging seems illuminated. When the squall
has passed the vessel about half a mile, the same
signs that characterized its approach from the
land reappear exactly, and before attaining the

TORNADOES PROPER. 159

same distance from the ship. The lightnings
again descend in continuous sheets, and in such
abundance that they resemble the torrents of rain
that accompanied the squall. These squalls occur
every day during a certain part of the year termed
the harmattan 1 season. The jet of black clouds,
coming from the mountains, begins to appear
about nine o'clock in the morning, and reaches
the sea about two o'clock in the afternoon.
Another singular fact follows these tornadoes.
After having whirled over an extent of eight or
nine leagues, they disappear, and flashes of light-
ning are beheld darting up from the sea. The vio-
lence of the wind during the storm is excessive.

" The circular motion of the air at the outset of
these tornadoes is indicated by the whirling about
of the leaves and straws that are caught up by it.
These meteors precede the rainy season, and are
more or less violent, according to the state of the
atmosphere. Ordinarily, they last but a little
while, and are always followed by a heavy shower,
which revives vegetation, and freshens the atmos-
phere, that had been made stifling by the blazing
heat. Hence, every one feels a vivifying sensation
of enjoyment after they are over."

1 The harmattan is a dry wind that blows from the interior of
Africa toward the Atlantic, principally in the months of Decem-
ber, January, and February.

160 METEORS AND METEORIC PHENOMENA.
CYCLONES. HURRICANES.

Piddington relates the meeting of two torna-
does, which, in violence, could be compared to
cyclones. The phenomenon was observed at
Charleston, in South Carolina, May 2, 1Y61, at
two o'clock in the afternoon :

" The tornado crossed the Ashley River, and
swooped down upon the shipping at Rebellion
Wharf, with such fury as to threaten the destruc-
tion of the entire fleet. From the city it was
seen coming at first rapidly toward Wappo Creek,
like a column of smoke, with a very irregular and
tumultuous movement. The quantity of vapor
that composed this column, and its prodigious
velocity, produced so intense a commotion that it
agitated Ashley River to its depths, and left the
channel bare. The ebb and flow made the ship-
ping float off to a great distance. "When it struck
the river, it made a noise like continuous thunder ;
its diameter, at that moment, was estimated at fif-
teen hundred feet, and its height, as seen from
Charleston, at twenty-five degrees. It was met, at
White Point, by another whirlwind, which descend-
ed Cooper River, but was not equal to the first.
When they came together, the commotion in the
air was much greater still; the foam and the

CYCLONES. 161

vapor seemed to be thrown to the height of forty
degrees, while the clouds, that hurried from all
directions toward that point, seemed to rush
thither and whirl about, at one and the same time,
with incredible velocity. The meteor then darted
upon the shipping in the roadstead, and reached
them in three minutes, although the distance was
nearly six miles. Out of forty-five vessels, five
were sunk on the spot ; the State ship Dolphin
and eleven others were dismasted. The damage,
estimated at more than £200,000, was done in a
moment, and even the vessels that sank were
swallowed up so rapidly that the people who were
below had scarcely time to scramble up on deck.
The whirlwind of Cooper River changed the
course of the one that came from Wappo Creek,
which, had it not been for that, would, pro-
ceeding in the same direction, have swept away
the city of Charleston before it like so much
straw.

"This terrible column was first perceived
about noon, at more than fifty miles west-south-
west of the roads. It destroyed every thing in its
way, making a complete avenue when it passed
through the woods. The loss of the five ships
was so sudden that it is not known whether it
was the weight of the column of wind, or the

162 METEOKS AND METEOEIO PHENOMENA.

mass of water driven upon them, that made them
go down."

It is near the Antilles, in the Gulf of Mexico,
and in the Indian Seas, that the most disastrous
hurricanes burst forth. These are the appalling
cyclones, during which Nature seems to return to
original chaos.

" Sometimes," says an old author, quoted in
the article on " ^Eolian Researches " in the Nauti-
cal Magazine for 1841, " sometimes, toward that
side of the horizon from which the storm comes,
is first seen something like a cloud blazing in the
most astonishing manner ; and some of these hur-
ricanes and whirlwinds have appeared so terrific
as to convey the idea that the entire atmosphere
and sea were in one tremendous blaze. Captain
Prowd, of Stepney, in one of his voyages to the
East Indies, encountered a storm of this kind, and
left some particulars concerning it, which I have
extracted from his journal. The sea was agitated
throughout, and what was the most astonishing
and terrifying circumstance was, that the sky be-
came surprisingly red and inflamed on the north-
ern part of the horizon. The sun was then at the
zenith. Signs of a tempest were recognized in
these appearances, and the storm came, as had
been foreseen. As the darkness grew thicker, the

HURRICANES. 163

violence of the wind increased until it attained
the proportions of an awful hurricane. At one
o'clock in the morning it beat with such force that
it was impossible to keep a sail on the vessel.
Seven men could scarcely steer. The whole at-
mosphere, the sky, and the sea, in their wrath,
seemed but one mass of fire."

An official account of the fearful hurricane
that devastated Guadeloupe on the 25th of July,
1825, contains the following passage :

" The wind at the moment of its greatest in-
tensity seemed luminous ; a silvery flame streamed
through the chinks in the walls, the key-holes, and
other openings, and made one think, in the dark-
ness inside of the houses, that the heavens were
on fire."

Sometimes, a dense bank of clouds of mena-
cing blackness is seen on the side of the horizor
from which the cyclone comes. Sheets of light
ning issue from it, the " terrible magnificence *
of which, according to Piddington, recalls the
splendors of the aurora borealis. At the same
time, the sea becomes covered with phosphores-
cent coruscations that fill the sombre night with
a pale radiance; while, during the daytime, a
blood-red sky spreads its sinister hue over the
whole horizon. A profound calm nearly always

164 METEORS AND METEORIC PHENOMENA.

precedes the hurricane, which is also announced by
" the distant moaning of the elements, as though
the winds were engulfing themselves in a vault.
These remote rumblings recall the sound of a
thunder-storm heard in caverns."

The sea assumes a murky color, breaks foam-
ing on the shore, and lifts itself sometimes in
enormous tidal-waves ( " the heavings of the tem-
pest " ), produced by the approach of the cyclone.
The elevation of the usual level of the waters,
which is almost always the sign of violent storms
or heavy rains, often causes inundations of low
shores beaten by the hurricane.

The diameter of this immense meteor varies
from fifty to one hundred miles, and sometimes
more. The disk of whirling air has probably
never more than from one to ten miles of vertical
height. Placed upon a summit, like the Peak of
TenerifFe, the observer would see it pass below
him, as travellers among the Alps often view
thunder-storms devastating the valleys at their
feet. In most of these cases, the disk of the
cyclone is so thin that the sky can be distinctly
seen through the black masses of cloud. Pidding-
ton quotes the following extracts from the log of
two sea-captains :

"We observed one very remarkable circum-

HUKKICAJSES. 165

stance : while, all around the horizon, there ap-
peared a bank of dense clouds, the sky at the
zenith was so perfectly clear that we could see the
stars ; and every one on board noticed above the
mizzen-mast-head a meteoric light of peculiar
brightness.

" While we were lying-to, the clouds were rent
asunder, and the sun, gleaming over the whole
surface of the water, gave the foam a tinge as
white as snow, and then as richly colored as the
rainbow in all its shadings."

Numerous observations tend to prove that the
disk of the storm is nearly always inclined for-
ward. While the front of the hurricane is at-
tacking the land or the sea, the rear rises, and
shows long trains of clouds, which are seen whirl-
ing about in the most extraordinary manner.
Strong discharges of electricity take place at the
same moment and announce the termination of
the cyclone.

The typhoons of the India Ocean are preceded
by the same signs, and accompanied by the same
phenomena, as the cyclones of the Atlantic, from
which they differ in some unimportant particu-
lars only. In the China seas, the strongest of
these hurricanes are termed " iron whirlwinds."

The frightful sea that they heave up ; the

166 METEORS AND METEORIC PHENOMENA.

tremendous violence of the wind, blowing in op-
posite directions from one side to the other of the
disk ; the dangerous calm that reigns at the cen-
tre, and leaves the ship motionless under the shock
of monstrous billows ; the cataracts of rain ; the
terrific din of the elements, — all unite to render
the struggle hopeless for the seaman. It is es-
pecially at night, in the midst of profound dark-
ness, under the livid lightnings, or in the strange
phosphorescent glare which sometimes envelops
the ship, that the horror of the spectacle defies
description. " If the winds are let loose in a
tempest," says Thomas Fuller, an old seaman,
"they become raging madmen in a hurricane."
In his voyage to the Isle of France, Bernardin de
Saint-Pierre gives a very exact description of a
hurricane that he witnessed :

" On the 23d of December, in the morning,
the wind being at the southwest, the weather be-
gan to work up for a gale. Clouds accumulated
on the summit of the mountains. They were
dark, olive, and copper colored. One long upper
band that remained motionless was noticed. The
clouds lower down were in swift motion. The
sea broke with a great noise on the reefs. Many
marine birds sought refuge on land and came fly-
ing in from the open expanse. The domestic ani-

HURRICANES. 167

mals seemed uneasy. The air was heavy and
warm, although the wind had not fallen. In
view of all these signs that foretold a hurricane,
everybody hastened to prop and brace his dwell-
ing and carefully to close all the openings.

"About ten o'clock in the evening the tempest
came on. First, there were fearful gusts, followed
by moments of appalling calm, in which the wind
seemed to recruit its strength. Thus it continued
with augmenting violence during the night. My
cottage having been badly shaken, I moved to an-
other shelter. My hostess was in tears for fear
that her house would be destroyed. No one went
to bed. Toward morning, the wind having be-
come still more violent, I saw that a whole front
of the surrounding palisade was about to fall, and
that a portion of our roof was lifting at one cor-
ner. So, with some boards and rope, I prevented
the damage. In crossing the yard to give some
orders, I several times expected to be thrown
clown. I could see walls falling in the dis-
tance, and fragments of ruin carried away, as
though they were cards. Rain fell at eight
o'clock in the morning, but the wind did not
cease. It was driven horizontally with so much
violence, that it entered in jets at the smallest
orifices.

168 METEOKS AOT) METEORIC PHENOMENA.

" At eleven o'clock, the rain fell in torrents.
The wind subsided a little, and in ravines of the
mountains on all sides prodigious cascades were
formed. Pieces of rock detached themselves, and
fell with a noise like that of a cannon, and as they
rolled down they forced great gaps in the woods.
The streamlets overflowed in the plain, which was
like a sea.

" At one in the afternoon, the wind leaped
round to the northwest, and drove the foam of
the sea in huge clouds upon the land. It threw
the vessels in port upon the shore, and they kept
firing guns of distress, but it was impossible to
help them. By those new concussions the houses
were shaken in another direction and with nearly
equal violence. The winds then made the com-
plete round of the horizon, as is usually the case,
and, after that, every thing became quiet again.

" A great many trees were blown down and
bridges carried away. Not a leaf was left in the
gardens, and even the grass, that strong, coarse,
tropical herbage, appeared in some places to have
been shaved off close to the ground."

Although these terrible meteors are chiefly
frequent in the torrid zone, they also appear some-
times in our temperate climates, on the Atlantic
and Mediterranean coasts. We shall presently

HURKICANES. 169

see how our meteorological observations can fol-
low them in their course, and warn the places
menaced by them in good time.

" These convulsions of Nature," says Peltier,
"seem necessary to reestablish the equilibrium
of the atmosphere, and often, notwithstanding the
terrors that they inspire, the inhabitants of the
countries that they ravage invoke them with all
their hearts.

" Dense, stagnant fogs, that cause disease, are
dispersed by the storm ; abundant rains reani-
mate life and spread freshness on all sides ; the
air becomes pure and light ; renewed by the
electric action of these tempests, it restores vigor
to men and animals, exhausted by the overwhelm-
ing heat of the burning season, and gives back
their brilliant verdure to the wilting plants. To
the commotion of the hurricane, the howling tem-
pest, the torrents of rain, the lightning, and the
thunder, succeed the serenity of the fine weather,
the calm, the pure light, and the beauty of an in-
comparable spring."

CHAPTER VII.

RAINBOWS.— CROWNS AND HALOS.

Description of the Rainbow.— Play of Light in the Drops of Water.—
Varied Appearances of the Arch.— Supplementary Arcs.— The Cir-
cles of Ulloa.— Crowns.— Colored Arcs.— Parhelia.— White Arcs. —
Anthelia.— The Halo of Clere*.

DESCRIPTION" OF THE RAINBOW.

" 0 Thou, Light, eternally one ! dwell there, on high, with the
Being eternally one! Thou, 0 changing Color! descend in
friendly guise to man ! " — SCHILLER.

]STo scene that Nature presents, better symbol-
izes this fine thought of the poet than the mag-
nificent arch, painted by the sun upon the dark
clouds of a retiring tempest. In all ages, the
rainbow has charmed the imaginations and awak-
ened a feeling of hope and consolation in the
minds of men. The Hebrew, impressed with the
remembrance of the former floods that came upon
the earth, felt his soul, that had been disquieted by
the thought, resume all its serenity as he beheld

mimm. ,,...... :

DESCRIPTION OF THE RAINBOW. 171

the bow of promise. For Mm it was the token
of Jehovah's pardon.

The gay fancy of the Greeks made the rain-
bow the presage of happy tidings to the earth,
the goddess Iris, the messenger of Olympus, ac-
cording to their creed, left her transparent scarf
floating on the clouds.

Ingenious fiction vanished at the approach of
science, and the explanation of the rainbow is,
to-day, one of the most complete parts we have
of the physical theory of light. It is to Kepler,
whose genius was prolific in so many directions,
that we are indebted for the discovery of the first
causes of the phenomenon ; he put it on record,
although very briefly, in a letter written by him
in 1601. Newton studied these causes with all
the rigor of geometrical calculation, and was
enabled to render an account of all the different
modifications observed in the rainbow. After
having calculated its dimensions, he verified the
correctness of his observations by actual experi-
ment.

"We never see the rainbow excepting when
standing with our backs toward the sun, the space
in front being traversed by a shower of rain, a cas-
cade, or a simple jet of water. When the sea is
agitated by a violent wind, and the sun's rays strike

172 METEORS AND METEORIC PHENOMENA.

the spray of the billows, rainbow curves and arcs
are often produced upon it.

Usually, the phenomenon consists of two con-
centric arches, with a considerable interval between
them. The centre of these, as it is easy to prove,
corresponds with that point in the heavens where
the shadow of the observer's head would fall.
The interior curve, which is the oftenest seen, pre-
sents a series of prismatic radiations, arranged in
such wise that the violet falls inside, and the red
upon the outside. In the external curve, the colors
of which are much weaker, the order of the series
is reversed. Sometimes three bows are seen, but
this occurs very rarely. The third, of an extreme-
ly pale hue, then presents colors arranged in the
same order as in the first instance.

The dimensions of these bows depend upon
the height of the sun above the horizon. It must
be close to the latter, in order to enable the ob-
server, standing on the surface of the ground, to
see arcs, or bows, embracing a half-circumference.
It is only from the summits of mountains, or from a
balloon high up in the air, that complete circles are
visible, unless, as they frequently do, they appear in
the spray of great waterfalls. A grand spectacle of
this nature is enjoyed in contemplating the mag-
nificent cascade of the Reichenbach. When we

WATERFALL RAINBOWS.

p. 173.

THE PLAY OF LIGHT IN DROPS OF WATER. 1Y3

saw it, the sun was rising, and the brilliant aerial
coronce, or crowns, were floating above the chasm
into which the waters plunged. Immense arches
of the same kind form upon the white mist that
rises over Niagara Falls.

The light of the moon also produces rainbows,
but the yellowish reflection that it spreads over
all the colors contrasts unfavorably with the vivid
hues of the solar bows. The principal arch can-
not be seen, and it is difiicult to distinguish the
variation of the prismatic rays. During a storm
which we witnessed on the open sea, we saw a
luminous column of the strangest appearance de-
scend from the sky. The ship's crew were struck
with terror, and yet the meteor was entirely harm-
less. The full moon was rising, tinged with red,
at that moment, and the column of fire was but a
fragment of a rainbow that it reflected on a sheet
of rain.

THE PLAY OF LIGHT IN DROPS OF WATEE.

All the appearances of the phenomenon of the
rainbow show that it is produced by a modification
of light taking place in the drops of water. These
drops are spherical, and, during a shower, follow
each other so rapidly at every point, that we may
reason concerning them as though they remained

174 METEORS AND METEOKIC PHENOMENA.

entirely motionless. The ray that penetrates the
drop of water is refracted and decomposed. Instead
of issuing from it undiminished, as it went in, it "re-
flects itself partly on the concave surface opposite
to the point where it entered, and passes back
through the globule, until it again meets the sur-
face; there, a similar subdivision takes place.
One portion of light passes into the atmosphere,
and the other is reflected. By a geometrical dia-
gram, it can be demonstrated that the drops,
which may send back to the eye of the observer
rays that have been reflected once, or several
times, are placed at certain heights, and form cir-
cular colored bands, each with a breadth equal to
the diameter of the image of the sun. The bands
corresponding to a single reflection are at an an-
gular distance of nearly forty degrees from the
centre. Those in which the light is reflected twice
are nine degrees farther off. In each group, the
differences arising from dispersion are small
enough to cause the bands to range themselves
one above the other, thereby giving rise to the
series, sometimes regular and sometimes reversed,
of the colors of the spectrum.

There is a simple ^method of accurately observ-
ing the passage of light through drops of water.
Suspend a globe of thin glass in a dark room by

THE PLAY OF LIGHT IN DBOPS OF WATER. 175

a cord passing over a pulley. When the globe
filled with water is so placed that a ray of light
allowed to fall upon it, through an orifice in the
window-shutter, forms an angle of nearly forty-
two degrees with the line that connects it with
the eye, all the colors of the spectrum, commen-
cing with red, can be seen, one after the other,
by merely lowering the globe gradually from
point to point. If the water be muddy, the pas-
sage of the ray can be observed, and we can see
that it undergoes but one reflection. When the
angle formed by the two lines is fifty-four degrees
in measurement, and the ray is made to fall upon
the lower part of the globe, the colors are ob-
served to form in like manner, and in the same
order, when the globe is gradually elevated. The
two reflections can then be easily distinguished in
the water.

According to the explanation thus given, the
rainbow is found to be purely a local phenomenon.
Each spectator sees a different arch. If the rainy
cloud be near, two observers, placed at some dis-
tance from each other, see the ends of their rain-
bows resting on different points of the ground.
This fact is particularly evident when one is
standing opposite to a mountain upon which the

bow is projected.
9

176 METEOES AND METEOEIC PHENOMENA.

YAEIOU8 ASPECTS OF THE BOW. STJPPLEMENTAEY

AECS.

The rays of the sun may happen to be re-
flected toward a cloud from the surface of a pla-
cid expanse of water, and this reflection also may
produce a rainbow. Calculation shows that, in
such a case, this arch must cut the arch directly
formed, at a height that depends upon the ele-
vation of the luminary. When these two phe-
nomena produce a secondary arch, the four curves,
thus interlaced, offer a very beautiful sight.
Monge narrates an instance where they were
complete in form and perfectly distinct. Halley
once saw three arcs, one of which was formed by
rays reflected from the surface of a river. The
latter arc first intersected the external arc in such
manner as to divide it into three equal parts.
When the sun descended toward the horizon, the
points of contact drew closer together. Ere long
there was but one, and, as the colors were in re-
versed order in the two rainbows, a space of per-
fect white was formed at this sole point by the
superposition of the two series. The sun, when
high enough above the horizon, may, when re-
flected from a sheet of water, form a complete
circle. Sometimes the upper part is wanting,

THE CIRCLE OF ULLOA. 177

and then there remains the singular phenomenon
of a rainbow reversed.

Supplementary arcs are often seen when the
rainbow is very brilliant. "We give this name to
colored bands observed inside of the interior and
outside of the exterior arch. After the violet, is
usually seen red, then green, and then violet
again. These colors may even be repeated sev-
eral times in the same order. It is on the cul-
minating part of the arch, and only when the lat-
ter is very high, that this phenomenon occurs. It
is explained by the laws of optics that relate to
refraction ; in other words, the modifications that
light undergoes in grazing the surface of bodies.

THE CIRCLE OF ULLOA.

Rainbows, in which the colors were extremely
faint, have been observed in dense fogs. This ap-
pearance arises from the diminutive size of the
drops of moisture. The great whitish ring, or
circle, seen by Ulloa and Bouguer during their
stay on the Pichincha, seems to have had this
origin. It has been called the White Rainbow, or
the Circle of Ulloa. Its dimensions are those of
the main arch usually seen, and it is perceived
only from elevated places, simultaneously with
the formation of rainbow-like halos around shad •

178 METEORS AND METEORIC PHENOMENA.

ows projected on the fog. We have reproduced
the description of this phenomenon given by
Bouguer, and will add what Ulloa says of it :

" He was on Pambamarca with six companions
at daybreak. The top of the mountain was en-
tirely covered with dense clouds. As the sun
rose, it dispelled these clouds, and nothing re-
mained in their stead but some very light mists,
which it was almost impossible to distinguish.
Suddenly, on the side opposite that in which the
sun rose, each of the travellers saw, at a dozen
fathoms from where he stood, an image of him-
self reflected in the air, as though upon a mirror.
This image appeared in the centre of three rain-
bows shaded with different colors, and surrounded
at a certain distance by a fourth arch of a single
color. The tinting farthest on the outside of each
arch was flesh-colored, or red, the next shade was
orange, the third was yellow, the fourth straw-
color, and the last one green. All these arcs
were perpendicular to the horizon; they moved
about and followed the person reflected in every
direction, surrounding his image like a gloria.
What was most remarkable was, that, although
the seven travellers stood together in a single
group, each of them saw the phenomenon only in
relation to himself, and was disposed to deny its

CROWNS, OR CORON^E. 179

existence in reference to the others. The extent
of these arches increased progressively in propor-
tion to the height of the sun. At the same time
their colors faded away, the spectra became paler
and paler and more vague, and at last the phe-
nomenon entirely disappeared. When this dis--
play began, the shape of the arcs was oval ; and,
toward the last, it was perfectly circular.

CROWNS, OR CORONJE.

When light clouds pass over the sun or the
moon, there may be perceived around those lumi-
naries one or more colored circles, known to me-
teorology as crowns. In all these circles, we dis-
tinguish the prismatic colors, the violet being
placed inside and the red outside. They are at an
equal distance from each other, but this distance
varies according to the condition of the clouds
and the atmosphere. The angular diameter of
the first circle is ordinarily comprised in from one
to four degrees.

" All clouds," says Kaemtz, " that are not too
thick to let the light of the sun pass through
them, the cirrus and the cirro-stratus excepted,
present traces of crowns, but the brightness of the
colors is not always the same. I have never seen
them so handsome as upon fogs which form, dur-

180 METEORS AND METEORIC PHENOMENA.

ing the night, in the valleys, and ascend, toward
the middle of the day, to the summits of the
mountains. When strips of cloud passed between
the sun and me, the colors had a vividness which
I have rarely seen in them. They are no less
fine on the cirro-cumulus, particularly when they
are in small masses of dazzling whiteness, and so
confused on their edges that it is difficult to trace
their outlines on the sky."

This phenomenon is, in its turn, explained by
the refraction of luminous rays passing near the
globules of water that compose the clouds. A
very simple experiment gives us an imitation of
the process. We have only to hold up before a
lamp a strip of glass besprinkled with lycopo-
dium, or vegetable sulphur. The fine grains of
the latter substance, acting as globules do, the
flame of the lamp is at once surrounded by pris-
matic rings, separated by equal intervals.

COLORED HALOS. PARHELIA.

In the phenomena of which we are about to
treat, small crystallizations of ice, and not glob-
ules of water, modify the light. We are some-
times surrounded by fogs formed of such par-
ticles. 'They frequently exist, as aeronauts have
ascertained, in the higher regions, of the at-

COLORED HALOS. 181

mosphere, where they form the clouds called
cirrus.

If the play of the luminous rays in the little
spheres we have been considering has given us
such pleasing phenomena, we may readily com-
prehend that, when they pass through limpid
crystals with numerous facets, we shall have fresh,
harmonious combinations of geometrical lines and
of colors to admire.

In temperate climates, the phenomena of this
order most frequently remarked are the halos, or
colored circles, that surround the sun or the moon,
but in a manner different from crowns. The ar-
rangement of the colors of the spectrum is usually
reversed in them, the red being placed inside.
The distances of the circles from the luminary are
equable, and much greater than in the corona.
Thus, the interior halo is from twenty-two to
twenty-three degrees in diameter; the second
halo, usually called the external one, measures
forty-six, and the third ninety-nine degrees in
diameter. Brewster imitated the halo by placing
a strip of glass, covered with crystallized alum, be-
fore a lamp. In order thoroughly to comprehend
the formation of this phenomenon, we must sup-
pose a very great number of prismatic needles sus-
pended in the air. These prisms, in certain posi-

182 METEORS AND METEORIC PHENOMENA.

tions, may revolve for a considerable period on
their own centres, without the deviation of the
refracted rays changing perceptibly. The multi-
plicity of these rays proceeding in any one direc-
tion, giving the eye a more vivid expression, col-
ored belts, or bands, are seen placed one above the
other, as in the rainbow.

"When the sun or the moon is near the hori-
zon, and the atmosphere remains calm, the needles
of ice arrange themselves vertically, and brilliant
spots, diffused images of the luminary, are formed
along the horizontal diameter of the halo and a
little outside of each circle. These take the name
ofjMrfa&a, or paraselene Parhelia, those of the
interior halo especially, are finely colored, all the
shadings of the spectrum following the red, which
is next to the sun. When the latter luminary
rises, the spots withdraw from the circles, remain-
ing, however, on the line of the horizontal diame-
ter.

Sometimes we see, resting upon the halos,
what are termed tangential arcs, or arches of con-
tact, of very brilliant color. The most frequent
are those that form symmetrically at the extremi-
ties of the vertical diameter of the halo, of twenty-
three degrees. Those of the external halo, which
are more rare, but more numerous at the time,

WHITE ARCS. 183

touch it, not only in the vertical line of the sun,
but also at the lateral points forty-five degrees
distant. The most elevated of these arches, which
has the zenith of the observer for its pole, is some-
times designated by the name of the circum-ze-
nithal circle,

We cannot, here, enter into details as to the
manner in which these appearances are produced
by the refraction of light in the crystals. M. Bra-
vais, in his learned researches on this subject, did
not confine himself to calculating all the circum-
stances of the phenomenon ; he succeeded in re-
producing it artifically, in a dark room, by means
of an ice-prism, which he caused to revolve very
rapidly while the rays of the sun were projected
upon it.

WHITE ARCS. ANTHELIA.

The appearances that we have now to describe
are always entirely white, a fact indicating that
they result, not from the passage of light through
the crystals, but from its reflection from their
facets. Their brightness is variable, sometimes
exhibiting only pallid gleams of light, and some-
times a dazzling splendor like that of the central
luminary. First, an immense circle, called ihepar-
heliac circle, crosses the sun or the sky, making the
two halos intersect each other, and spanning the

184: METEORS AND METEOKIC PHENOMENA.

whole horizon at an invariable height. Upon this
circle, and opposite to the sun, its image is repro-
duced alone, or accompanied by two others, which
take their places symmetrically beside it. Some-
times these images, or anthelia, are crossed by
two white arches, which extend to a considerable
distance. Vertical columns are also seen to form,
in other words, luminous trains, that extend twen-
ty-five degrees above and below the luminary,
thus forming, with a portion of the parheliac cir-
cle, a cross, with limbs more or less unequal.

According to the scwant Babinet, an imitation
of the parheliac circle is produced when the sun
is looked at through a crystal of fibrous structure,
cut in laminae parallel to its fibre, and placed in
a vertical position. The white horizontal belt
which is then seen results from the coruscation of
these fibres. Bravais has explained this phenom-
enon, as well as those of the anthelia, and their
arcs, by means of his ingenious apparatus.

Some physiologists attribute to the effects of
the mirage, the false suns and false moons that
are sometimes seen beside the real luminary when
it is near the horizon, but the same phenomena
may be explained by the interposition of an in-
finite number of small crystals composed of prisms
and pyramids.

ANTHELIA. 185

We sliall not enter further into details of the
appearances that halos present. We should have
to add other curves and other disks, due to quite
infrequent crystalline combinations, and we should
become involved in too many complex forms and
colors. Let us merely add, that very brilliant
parhelia and arches themselves become sometimes
sources of light that cause similar duplicate phe-
nomena, which, however, are naturally very faint.

In the illustration given are seen the principal
parts of halos. We must suppose the white hori-
zontal belt to be prolonged to the side of the
heavens opposite the sun, where the image of
that luminary is repeated several times. But the
phenomenon scarcely ever has its complete devel-
opment. Sometimes it is one and sometimes an-
other form of crystals that is produced in the at-
mosphere, and these diminutive bodies float there,
or descend slowly, in different positions, accord-
ingly as the air is calm or agitated. The parts
that we have represented are, consequently, seen
together but seldom, and it is not surprising,
therefore, to find a great variety of different
accounts by different observers.

It is generally noticed that the sky, on the
inside of the halo of twenty-three degrees, is in
striking contrast, by its dark-gray color, with the

186 METEOES AND METEOEIC PHENOMENA.

general illumination of the external space. This
peculiarity is explained by the direction of certain
rays, refracted by the prisms which produce the
halo. As in rainbows, there is a great difference in
brightness between the solar and the lunar halos.
In the latter, the colors are always very dull, but
the white parts of the great geometrical figure,
when it is formed, always throw back a beautiful
silvery light.

THE HALO OF CLEEE.

A remarkable display of halos and paraselenes
was observed on February 21, 1864, at eight
o'clock in the evening, in many localities of the
Departments of Indre-et-Loire and Loire-et-Cher,
in France.

" It was at Clere that the phenomenon pre-
sented the most curious appearance.

" The sky was clear and cloudless, and even the
stars could be seen, notwithstanding the moon-
light.

" All at once, rays of a silvery white, darting
apparently from the moon, described a Greek
cross, of which the moon occupied the centre. A
white ring of a deeper tinge connected the arms
of the cross, and thus formed a first and magnifi-
cent lunar halo.

THE HALO OF CLERE. 187

u At each arm, one extending to the north
and the other to the south, and at equal distances
from them, the image of the moon was reproduced
by a luminous globe of the same size, half white,
and half tinged with the colors of the rainbow.
These globes sometimes darted out luminous rain-
bow-colored rays, like the tail of a comet.

" A second halo, in an immense circle outside
of the first one, and starting from the luminous
globes that tipped the arms of the cross, surround-
ed the borough of Clere. It was of exactly the
same color as the first one. This second halo also
displayed two luminous globes, in all respects
similar to the first pair, at an equal distance on
its circumference. Thus, there were five lumi-
nous globes, including the moon, all connected by
the rings and the branches of the cross.

" What was still more curious was, that two
crescents of unequal size, and placed at a certain
distance one above the other, occupied the centre
of the second halo above the cross, without any
direct association with the rest of the phenome-
non."

At Mettray, the appearance was as follows:
" The silvery circle around the moon was cut
by two perpendicular luminous diameters. One
of these, running northeast and southwest, exhib-

188 METEORS AND METEORIC PHENOMENA.

ited at each extremity the hues of the rainbow.
These two points, thus rich in coloring, projected
of themselves, beyond the circle, a long, luminous,
but colorless train, affecting the form of part of
an ellipse.

"The phenomenon passed through different
phases, in consequence of the displacement of the
clouds, or more probably of the snowy mass in-
terposed between the moon and the eye of the
spectator.

" The luminous diameters disappeared slowly,
and the circle became gradually depressed, so as to
assume a completely elliptical form. The curve
at the same time became tinted with the colors of
the rainbow, but dimmer than they, while the two
extremities of the long diameter, which had been
prismatically variegated since the first appearance
of the halo, continued to show great luminous in-
tensity."

To conclude : at Amboise, the phenomenon
presented features no less remarkable :

" In fine, clear weather, that left the stars plain-
ly distinguishable, the full moon however being
slightly clouded, there gradually appeared a halo,
or luminous circle, of considerable dimensions,
with the moon in the centre. At the same time,
another circle formed, no less in breadth than the

THE HALO OF CLERE. 189

first one, but much greater in upward length, and
the moon occupied a point in its circumference,
to the southward. The two circles intersected
each other, and the refracted light being in some
sort accumulated at the two points of intersection,
situated to the eastward and westward of the
moon, two luminous foci were seen there, which
gradually displayed all the colors of the rainbow,
perfectly visible and perfectly distinct."

CHAPTER VIII.

THE AURORAL LIGHTS.

General Description.— Icy Fog.— Noise and Odor.— Electrical Currents.
— Magnetic Influence. — The Aurora Australia. — Different Points of
View.— Periodicity of the Auroral Lights.

GENERAL DESCRIPTION.

MANY hours, and sometimes a whole day, be-
fore the appearance of the aurora borealis, irregu-
lar movements are observed in the magnetic nee-
dle. During that time its deviation to the west,
or declination, sensibly augments. Little by lit-
tle, toward the north, the atmosphere thickens
along the horizon, and a curtain of violet mists,
thin enough to let the stars be seen through them,
begins to ascend. Its upper border brightens
feebly at first, and then this illumination becomes
more and more regular, and forms an arch of a
pale-yellow hue, turning its concavity toward the
earth, and with its summit in the meridian.

This arch ascends slowly, and gradually be-

GENERAL DESCRIPTION. 191

comes more luminous. Striated rays of blackish
tint assume shape, and a sort of effervescence is
observed along the entire extent of the arch. Ere
long, other rays shoot up of various length and
brightness, and dart into the sky, like rockets.
The fiery train, which at times is dazzling, passes
from purply-red to emerald-green, but most usu-
ally a magnificent yellow tinge predominates.

In their upward flight, these rays go beyond
the zenith, and seem to converge toward the same
point in the sky, namely, the magnetic zenith, in-
dicated by the prolongation of a magnetic needle
freely suspended.

In order to depict the suddenness of the varia-
tions of light in the rays, Bravais, like ourselves,
says that they dart. Occasionally, they are so
multiplied that they invade the entire celestial
vault, forming an immense cupola of fire, agitated
like the billows of the sea. No description could
do justice to the splendor of this spectacle.

With the first streaks of the aurora, the mag-
netic needle is subjected to lively oscillations.
These augment when the rays appear. Each one
of them, as it shoots from the arch, makes the com-
pass, in some sort, palpitate, and then sailors say
that it is lewitcTwd. Intervals of tranquillity, that
grow more and more frequent, next mark the de-

192 METEORS AND METEORIC PHENOMENA.

clining phase of the aurora, and it has been as-
certained that the deviation of the needle then
takes place in the inverse ratio of its declination
when the phenomenon began.

M. Lottin, intrusted, in common with M. Bra-
vais, with a scientific mission to Iceland, describes
a remarkable undulating motion that may be
noticed in the auroral beams when watched atten-
tively.

" While the arch," says he " is ascending tow-
ard the zenith, with every additional foot, the
brightness of each beam successively gathers in-
tensity. This kind of luminous current displays
itself several times in succession, and much more
frequently from west to east than in the opposite
quarter. Sometimes, but rarely, a retrograde
movement takes place immediately after the first
one, and as soon as the glow has run through all
the beams, one after the other, from west to east,
it changes to the opposite direction, thereby re-
turning to its point of departure, without our
being able to say whether it is the rays that are
thus carried across by a nearly horizontal move-
ment, or this brighter light speeding from one
beam to the other, step by step, without the latter
undergoing any displacement."

We shall see, further on, that this appearance

GENERAL DESCRIPTION. 193

arises, in reality, from a transfer of the beams
themselves.

Sometimes, when the ends of the auroral arch
have left the horizon, and it is rising higher in the
sky, the alternate motion of the rays attached to
it make it look like a long, golden drapery float-
ing in the atmosphere, folding and reopening in a
thousand ways, and undulating as though agitated
by the wind. This first arch fades and dies out
by degrees as it ascends, but, in the mean time,
new ones present themselves, some of them com-
mencing diffusely, and others with beams already
formed. Nine arches have been counted at one
time, forming in this manner, and passing through
nearly the same phases.

In the region toward which the beams con-
verge, there often appears a luminous, elliptical
curve, called the boreal corona^ or crown. It
seems to be merely an effect of perspective. The
rays, running parallel to the magnetic needle
freely suspended, are disposed like the ridges of
a cylindrical tunnel, which are seen converging
toward the centre of the two openings. When
this corona appears, the aurora is in its complete
development. It does not remain long visible,
however, and the phenomenon soon enters upon

its declining phase. The beams become more
10

194: METEORS AND METEORIC PHENOMENA.

sparse, shorter, and less vividly colored. " Bundles
of rays," says M. Lottin, "belts, and fragments
of arcs, appear and disappear at intervals. Then
the beams become more and more diffused, until
they are seen only as vague and feeble gleams,
which, at last, spread over the whole firmament,
grouped together like small cumuli^ and designated
by the name of auroral flakes. Their milky- white
radiance often undergoes very vivid changes of
intensity, similar to dilating and contracting
movements, which are propagated from the centre
to the circumference, and recall those of the marine
animals known as medusce. The twilight phase
comes on, little by little, and the phenomenon,
gradually fading away, at length ceases to be
visible. At other times, the rays still appear at
daybreak, and then suddenly vanish ; or, as the
morning twilight grows brighter, they become
more vague, assume a whitish color, and end by
commingling and losing themselves in the cirro-
stratus, in such manner that it is impossible to
distinguish them from that species of cloud."

ICE-FOGS.

Our remarks, just made in reference to the last
phase of auroras, indicate their relations with the
clouds composed of small crystals of ice. It is

ICE-FOGS. 195

very easy to make out, by daylight, those foggy
points in the sky which were seen in the form of
auroral flakes, while they were illuminated by
electricity, which is the first cause of the phenom-
enon. Sometimes, also, trains of cirrus are per-
ceived in the region where the most brilliant
beams were seen. Admiral Wrangel remarked
that halo arches formed around the moon at the
moment when auroral rays darted in the direc-
tion of that luminary.

" During the daytime," said Humboldt,
" clouds sometimes group together, and arrange
themselves almost like the rays of an aurora l)ore-
alis, and then they seem to disturb the magnetic
needle." Father Secchi, the director of the ob-
servatory at Rome, has also established the fact
that magnetic perturbations manifest themselves
at night when light phosphorescent clouds veil
the heavens. These are, in a certain degree,
feeble aurorce. Every body has had a chance to
notice the Polar belts described by Humboldt.
These clouds are disposed in long parallel lines in
the direction of the magnetic meridian, and are
seen quite frequently in our climates. M. de
Tessan, in his account of the voyage of the Yenus,
reports that one of the officers of the frigate al-
ways predicted fine auroras from having observed

196 METEORS AND METEORIC PHENOMENA.

the arrangement of the cirrus during certain
days.

In Canada, meteorological registers have been
kept, for a long time, which indicate the state of
the atmosphere on days that precede and follow
auroral displays. On nearly all those days there
has been either snow or rain, a circumstance which
renders it very probable that icy particles were in
the atmosphere during the presence of the aurora.
This infinite quantity of extremely delicate crys-
tals, traversed by electric currents, constitutes, as
it were, an immense luminous net- work floating in
the atmosphere.

It must be borne in mind that all these delicate
needles of ice may exist in the air while the sky
continues to look perfectly serene. Doctor Rich-
ardson, in fine weather, and at a temperature of
thirty-two degrees (centigrade) below zero, saw
the arc of the aurora in the neighborhood of the
zenith, and, at the same moment, remarked the
fall of an extremely fine snow, which was scarcely
visible, but which left drops on his hand in melt-
ing.

The existence of the 'fog that is seen on the
horizon, in the form of a darkish segment, before
the commencement of this luminous phenomenon,
confirms the preceding observations. In north-

NOISE AND ODOR. 197

era countries, travellers have found themselves,'
when on the summits of mountains, suddenly en-
veloped in a transparent mist of a grayish color,
bordering on green, which then became trans-
formed, in a higher region, to a splendid aurora
borealis.

NOISE AND ODOR. ELECTRIC CURRENTS.

When the point of observation is sufficiently
near the aurora, there is heard a peculiar rustling
sound, mixed with sudden crackling noises, analo-
gous to those produced by electricity when it
escapes from a body in the form of an aigrette or
a sheaf. Frequently a sulphurous smell is in the
air, and this is due, no doubt, to the ozone which
is produced during the electric discharges of the
pole, as it is in a thunder-storm.

When treating of storms, we said that the
atmosphere is constantly charged with positive
electricity, produced in great part in the tropical
regions. The earth, on the contrary, is negative-
ly electrified, and a neutralization is effected by
means of the humidity of the lower strata of the
atmosphere. Says De la Rive, to whom we are
indebted for this theory : "It is principally in the
polar regions, where the eternal ices condense the
aqueous vapors incessantly in the form of fog, that

198 METEORS AND METEORIC PHENOMENA.

this neutralization should take place ; and, with
the greater reason, that the positive vapors are
borne thither and accumulated by the tropical
current, which, starting from the equatorial re-
gions, where it occupies the highest range of the
atmosphere, descends as it advances toward the
more elevated latitudes, until, in the vicinity of
the poles, it comes in contact with the earth. It
is there, then, that the discharge of the positive
electricity of the mists, and the negative electri-
city of the earth, should essentially take place,
with an accompaniment of light, when it is in-
tense enough, if, as is almost always the case near
the poles, and sometimes in the upper parts of
the atmosphere, it encounters in its course parti-
cles of ice of extreme tenuity which form the fogs
and clouds very high up in the air."

According to the more or less foggy condition
of the atmosphere in the polar regions, and there-
fore its greater or inferior capacity as a con-
ductor, the two electricities more or less readily
neutralize each other. Hence arise currents of
variable intensity that traverse the surface of the
earth from the pole to the equator. It is the in-
fluence of these currents upon the magnetic needle
which produces the deviations and oscillations
that we have signalized.

ELECTRIC CURRENTS. 199

These perturbations are continual in the high-
est latitudes, because the intensity of the elec-
tric currents is greater, and their influence more
marked. In proportion as we descend toward
the equator, we notice fewer de\7iations, but still
they take place to some extent everywhere, even
in places where the aurora is not visible. For
several years Arago, in following the variations
of the needle at the observatory of Paris, was able
to announce the appearance of the aurora borea-
lis in the Eastern Hemisphere, without being once
mistaken.

During the fine aurora of November 27, 1848,
Signor Mateucci observed the influence of the
currents in a very remarkable form. He writes :
"I was at the electric-telegraph office in Pisa,
when we were suddenly surprised by the appa-
ratus ceasing to work, although it had always
operated perfectly well in the daytime. The
same thing happened at the same moment in
Florence. We tried to make it go by increasing
the force of the currents, and then by acting
upon the manipulators ; but all in vain, — the
anchor remained attached to the electro-magnets."
This singular effect ceased when the aurora dis-
appeared, and the apparatus again performed its
task as perfectly as ever. In England, Mr. High-

200 METEOES AND METEORIC PHENOMENA.

ton has recorded the very prolonged effect of the
aurora upon the telegraph-wires.

In all parts of the European net- work of tel-
egraphs the working of the wires was disturbed
by the magnificent aurora of August 28, 1859.
Two days later, the luminous phenomenon was
perceived over a great part of the continents of
Europe, Asia, and America, and a magnetic action
still more general was noticed. There were cur-
rents sufficiently intense to cause a spark to be
thrown off when they were interrupted. In the
United States, two telegraph-operators, stationed
at Boston and Portland, were able to use the terres-
trial fluid, which was much more powerful than
that of the machine, and kept up a conversation
for some time.

MAGNETIC INFLUENCE.

Let us now consider the great mass of lumi-
nous fog placed in the icy zone, and acting as a
species of movable conductor traversed by a suc-
cession of electrical discharges. The globe being
considered a huge magnet, what is the action of
the magnetic pole upon this fog ?

To M. de la Rive we are indebted for a very
interesting experiment in physics, which has put
us in a way to solve this problem. He took a

MAGNETIC INFLUENCE. 201

hollow ball of glass, in which the air was extreme-
ly rarefied, and arranged inside of it an apparatus
causing jets of electric light to converge upon the
pole of an electro-magnet. He states the result
as follows : " As soon as the cylinder of soft iron,
which serves for an electro-magnet, is magnetized,
the electric light, instead of starting indifferently
from different points of the upper surface, which
serves as a pole, as it did before being magnetized,
parts from all the points of the circumference of
that surface, in such manner as to form a sort of
continuous luminous ring around it. That ring
has a kind of rotary movement around the mag-
netized cylinder, sometimes in one direction and
sometimes in another, according to the direction
of the discharge, and the sense in which the mag-
netizing was done. Finally, some jets of light
more brilliant than the rest seem to shoot forth
from this luminous circumference, without becom-
ing confounded with the rest of the sheaf of rays.
As soon as the magnetic state ceases, the luminous
phenomenon becomes what it was before."

Relying upon this experiment, M. de la Rive
constructed an apparatus consisting of a wooden
sphere, with a covering of soft iron, to represent
the earth. With this apparatus he was able to re-
produce not only the polar aurora but also the

202 METEORS AND METEOKIC PHENOMENA.

different effects that they determine, such as the
disturbance of the magnetic needle and the move-
ments of electricity in the telegraphic wires.

"We have said that the arc of the aurora 'bore-
alls always has its summit placed in the mag-
netic meridian. In the great aurora of the au-
tumn of 1859, the arc appeared to have its centre
toward the northwest in California, nearly at the
north in Philadelphia, and toward the northwest
in England. This would place the real centre in
North America. A great number of like observa-
tions have led to the same result, and the aurorse
thus present themselves to us as luminous rings
of variable diameter, centred around the magnet-
ic pole, and hovering at a greater or less height
in the atmosphere, shooting forth vertical rays.
The undulating movement of the arch, and of the
radiations emanating from it, described by M.
Lottin, which would seem to indicate their rota-
tion from the west to the east, passing up by the
Bouth, adds another feature of resemblance be-
tween the great phenomenon and the experiment
of M. de la Hive. In fact, it is in this sense
that the ring should turn when the positive elec-
tricity issuing from the atmosphere is directed
toward the north magnetic pole.

The form and movements of the aurora are

THE AURORA AUSTRALIS. 203

therefore determined by the forces which emanate
from the grand terrestrial magnet. And we may
add a remarkable observation of M. Hansteen:
" During the aurora, and for several days after-
ward, the magnetic intensity is notably dimin-
ished, and recovers its usual value only by de-
grees."

THE AURORA AFSTRALI8.

Judging from such few observations as have
been collected in the southern hemisphere, it
may be said that the aurora australis, or southern
aurora, presents the same phenomena as the au-
rora borealis. It is explained in a similar manner.
Several cases of coincidence between the illumina-
tions of the two poles have been remarked.

M. de Tessan has given the following descrip-
tion of a southern aurora, observed during the
voyage of the Yenus : " On January 20, 1839, at
twenty minutes past one o'clock in the morning,
we noticed a fine aurora forming a very apparent
and clearly-marked luminous arc of a circle. Its
radiance was white; there may, however, have
been a slight greenish tinge, for it reminded one
somewhat of the light of a phosphorescent body.
This light was soft and steady, and might be com-
pared, as to brightness, with that of the upper

204: METEORS AND METEORIC PHENOMENA.

edge of a cloud of the cumulus order from behind
which the moon is just emerging. Flashes, or
beams, equally white, but of much less intensity,
rose from different points of the arc. These
flashes appeared and disappeared, very perceptibly,
in the same place, after a variable duration of
from five to ten minutes.

" The lower part of the arc seemed to be occu-
pied by a large black cloud, the borders of which,
adjacent to the arc, were slightly notched. I took
this appearance for a real cloud ; I noted it as
such, and not a doubt on the subject would have
entered my mind, had I not, since my return, seen
similar appearances cited as deceptive by skilful
observers, who assure us that they could see the
stars through this apparently dense cloud.

" The sky was quite clear, and only dotted
with a few large clouds, while the stars were very
brilliant. "We heard no particular noise from the
direction of the aurora."

DIFFERENT POINTS OF VIEW. THE PERIODICITY OF

AURORAS.

Frequently, observers at the north have found
themselves placed in the middle of the aurora,
below the luminous ring. At that time the arch ex-
tended beyond the zenith, and in a great measure

DIFFERENT POINTS OP VIEW. 205

concealed the trajectory of the rays. It is in these
conditions that the noise of the electric discharges
becomes perceptible, as well as the smell of ozone.
The curious circumstance has been remarked, that
the magnetic needle remains completely motion-
less there, while it is keenly agitated everywhere
else on the surface of the globe. The direction
assigned by theory to the currents accounts for
this effect.

In our middle latitudes, the aurora borealis
usually displays itself in a coloring of the sky,
which looks like the reflection of a conflagration.
"We likewise, but less often, see large, reddish
clouds, from which sometimes shoot forth beams
that ascend to the zenith. Before this meteor was
completely understood, and admired for its beauty,
and for the solace afforded by its brilliant illumi-
nation during the long polar nights, it was in
Europe a source of terror. In antiquity and the
middle ages, those red flames, those shooting
rays, seemed blazing torches, and swords dipped in
blood. The imagination at one time depicted an
immense conflict, in which men of fire struggled
for mastery ; and, at another, an assemblage of
hideous heads tossing their flaming tresses.

The aurora borealis is not always visible. It
is, very probably, a phenomenon that frequently

206 METEORS AND METEORIC PHENOMENA.

occurs in the daytime. During a winter passed
at Bossecop, in the seventieth degree of latitude,
M. Lottin counted one hundred and fifty aurorae
in two hundred nights. Naturally, the number
of appearances of the phenomenon grows smaller
as we recede more and more from the magnetic
pole.

An annual periodicity has been remarked in
the visible auroras, the number of which increases
as we approach the equinoxes, and diminishes at
the epoch of the solstices. These fluctuations must
depend upon the greater or less abundance of va-
pors carried toward the poles during different
seasons. At the equinoxes, circumstances are
perceptibly the same in the two hemispheres, and
it is also at this epoch that the simultaneousness
of the boreal and austral auroras has been noted.

CHAPTER IX.

SHOOTING-STARS.

Fire-balls.— Showers of Stones.— Meteoric Stones.— An Extraordinary
Meteor.— Velocity and Appearance of Fire-balls.— The Fall of Aero-
lites.—Periodical Reappearances.— Composition of Aerolites.— Dark-
ening of the Sun.— Ring of Meteorites.

FIRE-BALLS.

EVERY one has seen the luminous furrows of
various colors, direction, and extent, which are
rapidly traced across the constellations, sometimes
by brilliant luminous points without apparent
diameter, and sometimes by globes of fire of divers
dimensions. The latter, which are spoken of as
fire-balls, or 'bolides, sometimes split into pieces at
the end of their course, with a loud report, and
leaving a small cloud at the point where they dis-
appeared.

Dazzling trains of light and blazing "bolides
have been seen in broad daylight, but very rarely.
During the night an average of ten shooting-stars

208 METEORS AND METEORIC PHENOMENA.

per hour is seen, but, in certain seasons of the
year, they cross the heavens in swarms, and nu-
merous fire-balls are sometimes interspersed with
these great displays.

Divers causes have been assigned for these
phenomena. Kepler believed them to be engen-
dered by " terrestrial exhalations," and this opin-
ion has been handed down to our day, with but
little modification. Most savants, however, have
adopted another way of accounting for them.
They attribute all these meteors to mineral mass-
es known by the name of aerolites, which, when
they fall to the ground, exhibit traces of intense
combustion. A passage in Plutarch shows that
the ancients had adopted that explanation: —
" Some philosophers," he says, in his life of Ly-
sander, "think that shooting-stars do not arise
from detached parts of ether coming to extinguish
themselves in the air, immediately after taking
fire ; nor do they spring from the atmosphere in
a state of dissolution, in great quantity, in the up-
per regions ; they are rather heavenly bodies that
fall to the earth, or, in other words, bodies with-
drawn in some manner from the force of rotation,
and precipitated, not only upon the inhabited
regions, but upon the great seas, whence it comes
that they are not afterward found."

SHOWERS OF STONES. ' 209

Diogenes of Apollonius mentions a star of
stone that fell " all on fire near ^Egos Potamos."
The fall of this aerolite made a great impression
on the inhabitants of Thrace. According to the
description that has remained to us, it was twice
the size of an ordinary millstone, and made a
whole wagon-load by itself. A shower of stones
fell near Eome during the reign of Tullus Hostilius.
In Galatia, Cybele was worshipped in the form of
a stone that had fallen from the sky. At Emesis,
in Syria, a similar stone was set apart for the
worship of the sun. These two meteoric stones
were subsequently transported to Rome.

SHOWEKS OF STONES.

Even as late as the eighteenth century, learned
men did not believe in stones falling from the sky.
It was only in 1794 that Chladni attempted to de-
monstrate the truth of the explanation which had
been stowed away among popular superstitions.
Not long afterward, in 1803, on the 26th of
April, a shower of stones fell upon the small town
of Laigle, in Normandy, and dispelled all doubt
on the subject. A regular statement was drawn
up, and the messenger of the Institute who went
to the spot made a report, which Humboldt has
quoted in his " Cosmos," as follows :

210 METEORS AND METEORIC PHENOMENA.

" At one o'clock in the afternoon, with the sky
perfectly clear, a large fire-ball was seen from
Alencon, Falaise, and Caen, moving through the
air from southeast to northwest. Shortly after-
ward there was heard at Laigle, for four or five
minutes, an explosion coming from a small and
almost motionless black cloud. This was followed
by three or four others, and a noise that one
would imagine was produced by discharges of
musketry mingled with the rolling of a great
number of drums. Each explosion detached from
the black cloud some of the vapors that formed
it. At that point no luminous phenomenon was
observed. More than two thousand meteoric
stones, of which the largest weighed seventeen
pounds, fell upon an elliptical surface ranging
from southeast to northwest, and about eleven kil-
ometres in length. These stones smoked, they
were burning hot, without being on fire, and it
was ascertained that it was easier to break them
within a few days after their fall than at a later
period."

METEORIC STONES.

Popular tradition being thus confirmed by
actual experience, all that could be remembered
of the observations of the ancients was brought

METEORIC STONES. 211

together, and efforts were made to collect new
ones. Howard, an English chemist, drew up a
chronological list of all the stones that had thus
fallen from the sky since the earliest times. This
list Chladni has completed. We select from it
the most remarkable instances that can be referred
to a determinate epoch :

Before the Christian Era. — The thunder-stone
that fell in Crete, and was held in veneration as
the symbol of Cybele. — The sudden shower of
stones which destroyed the enemies of the Jewish
people at Beth-horon, as told by Joshua. — The
sacred shield that fell in the reign of ^Turna. —
The black stone kept in the Kaaba, at Mecca. —
The thunder-bolt, hard and glittering, from which
the sword of Antar was fashioned.

After the Christian Era. — Fall of a stone
weighing two hundred and sixty pounds at En-
sisheim, in Alsace. This enormous stone was
kept for a long time on the altar of the village
church. — A stone of black metallic color, of the size
and form of a human head, and weighing fifty-four
pounds, fell on Mount Yaison, in Provence. — A
stone fell in a fishing-boat in Copensha. — A stone
fell at Larissa, in Macedonia ; this stone, which
emitted a sulphurous odor, and had the appearance
of iron in ebullition, weighed sixty-two pounds. —

212 METEORS AND METEORIC PHENOMENA.

A great shower of stones at Barbotan, near Roque-
fort. Some of the fragments were from twenty-
eight to thirty pounds in weight; one of them
penetrated a cabin and killed a shepherd and a
young bull. — A shower of stones at Cutro, in Ca-
labria, during the fall of a great quantity of red
dust. — Stony masses fell in the Baltic Sea just
after the great Gottenburg meteor.

At four o'clock, in the afternoon of the 13th of

7

September, 1J868, there was seen at the village of
Luce, two leagues from Chartres, in France, a dark
cloud, from which detonations were heard, and
these were followed by the whistling or hissing
sound that accompanied the fall of a black stone.
The latter, which nearly buried itself in the soil,
weighed seven pounds and a half, and was so burn-
ing hot that no one could touch it. — The stone
that fell at Angers, June 9, 1822, was attrib-
uted to a beautiful shooting-star seen at Poi-
tiers. Humboldt relates that this meteor had the
effect of a Roman candle in a display of fireworks,
and left a train in a straight line of such glowing
brilliancy that the light lasted for several min-
utes.

AN EXTRAORDINARY METEOR.

In a letter addressed to M. A. Quetelet, the
permanent secretary of the Royal Academy of

AN EXTRAORDINARY METEOR. 213

Belgium, with regard to a remarkable meteor ob-
served at Hurworth in October, 1854, Sir J. Her-
Bchel quotes the following description, which we
give substantially as it appeared in the Sheffield
Times. It was published by a person living at
Hurworth, who, in company with his brother, saw
the phenomenon :

" My brother and I were returning home at
nine o'clock in the evening, and had just reached
the end of the village, and were about to cross a
meadow of considerable breadth. The sky was
clear and starry, but dark. "We were looking at one
of the brightest constellations, when, at the very
point on which our gaze was fixed, we beheld a mag-
nificent sight. A cry of admiration and astonish-
ment escaped us both. What we saw was a globe
of fire, at least double the size of the moon when
it rises. It was as red as blood, and shot out
sparkling rays, which were marked in sharp out-
lines, as old engravings represent the rays of the
sun. It drew after it a long trail of light of the
most beautiful limpid golden color. The train
had no resemblance to the hairy tail of a comet,
but was more like a solid column, of great breadth
and perfect compactness, standing out against the
deep blue of the sky. In the beginning it pre-
sented the appearance of a straight line, but as it

214 METEORS AND METEORIC PHENOMENA.

mounted the heavens, it described the curve of an
arch with sparkling scintillations of great inten-
sity, which, however, did not pass beyond the
well-defined exterior line. Its direction was from
northeast to southwest, and its length so enor-
mous that, when its nucleus was disappearing
under the southwestern horizon, the tail was still
visible at the northeast in all its original splendor.

"When this globe of fire was immediately
above us, it seemed to pause for a moment with
vibrations so violent that I was afraid it would fall
on us. But, the next instant, I saw that the vibra-
tion was only a whirling motion, and that it was
turning rapidly on its axis, passing from a vivid
fiery red to the deep red mentioned above, with-
out, however, losing any thing of its general ap-
pearance. We continued to see it, looking as
brilliant as ever, behind the trees on the other side
of the village. While this globe was passing over
us it seemed a little smaller than when it first ap-
peared on the horizon, no doubt because of its
great elevation, just as the sun and the moon
look smaller at their meridian than when they
are rising.

" As I have been, for a long time past, in the
habit of watching the stars, I have seen several
brilliant meteors, but never any that could bear

AN EXTRAORDINARY METEOR. 215

the least comparison to this one, whether for di-
mensions or for splendor and duration. Owing
to its height in the air, it must have been visible
at a great distance, and I hoped that it would
have been seen and described by intelligent ob-
servers. As such, however, has not been the case,
I have thought it my duty to furnish some details
concerning a phenomenon so grand and striking."

According to Sir John HerschePs letter, this
phenomenon was seen, in like manner, by many
other persons, at Darlington, at Durham, and at
Dundee, in Scotland :

" It is quite remarkable that, in consulting the
register which records the observations made of
the famous meteor that crossed England on the
18th of April, 1783, we found that it was seen at
Windsor about nine o'clock, which was precisely
the hour at which we saw this one, my brother
having looked at his watch at the moment of its
appearance. The meteor of 1783, having appeared
during the twilight of a summer evening, would,
no doubt, have been more generally observed than
the latter phenomenon, which showed itself in a
dark night at the close of autumn. But, for this
very reason, the latter should have been much
more brilliant than the former one, and it is to be

regretted that the lateness of the hour, or rather
11

216 METEORS AND METEORIC PHENOMENA.

of the season, should have prevented it from being
as generally observed.

" ISTo noise, accompanying its passage, reached
us. Those who saw the enormous globe of fire,
sweeping across the sky with inconceivable veloci-
ty, will never forget that magnificent and wonder-
ful meteor. In beholding unrolled above us that
splendid train of light, which covered more than
half of the sombre vault of the heavens with a
golden arch, we involuntarily thought of the spec-
tacle that must be presented to the eyes of the
inhabitants of Saturn by the ring that encircles
that planet. The tail, near where it ended, broad-
ened enormously ; it seemed more transparent,
and less compact, yet with well-defined outlines,
and rounding off at the extremity. The illustra-
tion accompanying this letter was sketched with
the hope of attracting general attention to an oc-
currence so interesting, rather than with any pre-
tension of giving even a feeble idea of this rare
and splendid phenomenon."

VELOCITY AND APPEARANCE OF BOLIDES.

The speed of these fire-balls is now calculated
with considerable accuracy, as will be seen from
the following extract taken from the researches of
M. Heiss, the director of the Minister Observatory.

TELOCITY AND APPEARANCE OF BOLIDES. 217

The superb bolide which he describes was seen,
on the 14th of March, 1863, in Holland, Belgium,
Germany, England, and France :

"Toward seven o'clock in the evening, the
meteor appeared in the sky like a shooting-star ;
but, little by little, it enlarged until it presented
an apparent surface comparable to a quarter of the
moon, and a brightness that made the stars visible
at the time seem pale. After having illumined
the horizon with a vivid light, which different ob-
servers have described as exhibiting all the colors
of the rainbow, from red to violet, the fire-ball dis-
appeared with an explosion. In many places,
sparks and a train were seen. The duration of
the phenomenon was about five seconds. The
trajectory, directed north and south, was inclined
twenty-two degrees to the horizon, and the length
of the arc — described from the point of inflamma-
tion to that of explosion, at about twenty-six kilo-
metres (sixteen and three-quarter miles) above the
surface of the ground — was two hundred and
eighty-five kilometres (one hundred and seventy-
seven, nine-hundredths miles). This indicated a
speed of one hundred and sixty-three kilometres
(thirty-nine, fourteen-hundredths miles) per second.
Four hundred and twenty yards was the real dia-
meter of the blazing globe, which must have been,

218 METEOES AND METEOEIC PHENOMENA.

generally, of a gaseous nature, with no solid nu-
cleus."

It is this extreme velocity, superior to that of
our globe in its orbit, which, with the resistance
of the air, accounts for the appearances presented
by these fire-balls. " The heat which the meteor-
ites possess," says Sir John Herschel, in his Astron-
omy, " when they fall upon the soil, the igneous
phenomena that accompany them, and their ex-
plosion, when they penetrate the denser layers of
the atmosphere, are all sufficiently explained by
the aid of physical laws. They are caused by the
condensation of the air, occasioned by their enor-
mous swiftness of translation, and by the relations
that subsist between highly-rarefied air and heat."
The explosion is attributed to the pressure sus-
tained by the solid mass. Calculation shows
that, at the height of eighteen kilometres, where
the density of the air is ten times less than at the
surface of the earth, a velocity of forty kilometres
would produce a pressure of six hundred and
seventy-five atmospheres. Iron might sustain
this, but it would cause a stone to burst. This
calculation is confirmed by actual observation :
aerolites composed almost exclusively of iron come
to the ground entire, but such as are of less solid
consistency fall in fragments.

VELOCITY AISTD APPEARANCE OF BOLIDES. 219

On the 14th of October, 1863, about three
o'clock in the morning, "M.. J". Schmidt, director of
the Athens Observatory, succeeded in following a
very remarkable bolide with the telescope. The
meteor in question appeared like a shooting-star,
rather slow in movement, between the constella-
tions of the Hare and the Dove. " It soon surpassed
Sirius in splendor. Its color was a clear yellow. It
passed Eridanus toward the west, shedding a light
so extraordinary that all the stars were eclipsed,
while the city of Athens, the country, and the sea,
looked as though on fire. The Acropolis and the
Parthenon stood out, a dead greenish-gray in hue,
against a background of golden-green sky."

At this moment M. Schmidt, resorting to his
telescope, was enabled to observe the meteor for
several seconds, and note a curious phenomenon :
There was not merely a single luminous body to
be seen, but he discovered two brilliant bolides
of a greenish-yellow, in the form of elongated
drops : the larger preceded the smaller, and each
left a red track, with well-defined edges. These
two bodies were, moreover, followed by luminous
bodies of less~size and similar appearance, irregu-
larly distributed, like sparks in the train of the
bolides. At the moment of its disappearance, the
meteor appeared divided into four or five frag-

220 METEORS AND METEORIC PHENOMENA.

*

ments, of a dark red. No noise was heard either
before or after the disappearance.

FALL OF AEROLITES.

We will cite, in addition, some details con-
cerning a more recent appearance of bolides and
the fall of aerolites in the south of France :

" Yesterday (May 14, 1864), at eight o'clock in
the evening," writes an observer at Castillon, in
the department of the Gironde, "a magnificent
meteor was seen by us in the vicinity of the moon,
and in an easterly course. It was visible for
about five seconds, during which time it swept
over an arc of more than sixty degrees. At last
it burst into smaller stars and disappeared.

" The apparent size of the meteor constantly
increased by progressive augmentations. A mo-
ment before disappearing, its diameter seemed
equal to at least half that of the moon. At first,
the light had a greenish-blue tinge ; then it be-
came white, and shone with such brilliancy that
persons badly situated for a direct view of the
meteor, thought they had seen the reflection of a
vivid and prolonged flash of lightning."

In many places distant from each other, a loud
detonation was heard, and an interval of some du-
ration elapsed between the visible explosion of

FALL OF AEROLITES. 221

the meteor and the hearing of the noise. Three
or four minutes were counted, and only two min-
utes correspond to a vertical distance of forty kil-
ometres. The atmospheric layers at that height
are greatly rarefied, and, in order that an explo-
sion taking place in those regions should cause a
noise of such intensity at the surface of the earth,
and over a horizontal extent so considerable, we
must admit that it exceeded in violence any thing
known to us.

Judging by the apparent height and dimen-
sions of the fire-ball, its diameter was estimated
to be from four hundred to five hundred yards.
It was then four or five times the size of the Paris
cathedral. M. Laussedat calculated that its ve-
locity was fifteen miles per second, or, in other
words, about two-thirds of the rapidity of the
earth in its orbit. Aerolites have been picked
up near Orgeuil, in the department of Lot-et-
Garonne, and in many neighboring places. M.
Daubree, who examined them, found that they re-
sembled terrene lignites. " In this black mass,"
he says, " may be distinguished small particles
of a metallic substance, of a bronzed-yellow color,
the density of which allows them to be isolated by
washing. Examining these little grains with a
microscope, I recognized some very compact crys-

222 METEOKS AND METEORIC PHENOMENA.

talline forms, but of very small dimensions. These
grains, or particles, are very strongly attracted by
the magnet, and possess all the physical and chem-
ical characteristics of the magnetic pyrites dis-
covered forty years ago in the meteoric stone of
Juvinas. The meteorite of Orgeuil should be
classified with the coaly meteors, of which the fall
of three only has thus far been recorded. The
surface of all the fragments was found to be fused
and vitrified ; however, the interior included sub-
stances which could easily be volatilized. These
two circumstances, apparently contradictory, may
be explained, if it be admitted that the heat un-
dergone by the meteorites was of such brief dura-
tion that it could not penetrate the interior of the
mass, the substance of which, moreover, was a bad
conductor of caloric. In the case to which we
are now referring, the heat must have been in
some sort instantaneous, yet of considerable in-
tensity, for it required the red-white heat of the
blow-pipe to reproduce artificially the varnishy
melted surface that is left by fusion. Not only is
the interior part of the meteorite tender and friable,
but it is reduced to impalpable powder, the mo-
ment that it comes in contact with water, and the
soluble salt that serves to cement it is dissolved."

COMPOSITION OF AEEOLTTES. 223

COMPOSITION OF AEROLITES.

In studying aerolites, and comparing them
with other minerals, savants have arrived at the
conclusion that they are indeed composed of the
same elements (nearly a third of the known simple
bodies), but that, in the method of aggregation,
they are entirely different, and must be regarded
as strangers to our globe. "Whatever may be the
date or locality of their fall, they have very
evident common characteristics, and this relation
is so striking that they might have been regarded
as having formed part of the same rock : on the
outside, a black incrustation, a glistening enamel,
produced by very high temperatures, but penetrat-
ing only a few hair-breadths ; and, in the interior,
a singular, granulated structure, presenting some
very strange features, which, when polished, might
be compared to hieroglyphics. An aerolite often
resembles a stone at which shot had been fired.
The granulations are sometimes extremely diminu-
tive, as in the specimen described above ; some-
times, as large as millet, as peas, or even as hazel-
nuts. They are hard, and, when broken, exhibit
crystallization. The matter in which they are in-
crusted is of an earthy nature, more or less con-
sistent, and ordinarily gray. The substances that

224: METEOKS AND METEORIC PHENOMENA.

compose it are for the most part mechanically
mixed, and not chemically combined. Aerolites
composed almost entirely of iron are put in a
class apart from the rest, so that they may be de-
composed in grains. It must be remarked that
this iron is in nowise oxidated ; that it is, as miner-
alogists say, in its native state, and that, with
the nickel, which it most usually holds in combi-
nation, stamps aerolites with a mark altogether
peculiar in its way.

Stony aerolites, formed by the mixture of dif-
ferent mineral substances, constantly have the ap-
pearance of fragments, and they are not found in
large masses, like those which are almost entirely
composed of iron. There have been some enor-
mous specimens among the last. The meteoric
mass observed by Pallas, on the plains of Siberia,
weighed one thousand five hundred and forty
pounds. It was held in veneration by the Tar-
tars, and regarded by them as having fallen from
heaven. A mass, found in Brazil, weighed fully
six tons and six-tenths. According to M. Beudant,
there is a similar mass, weighing fifteen tons and
eight hundred pounds, at Olimpa, in the Tucuman
country, and one of fifteen and nine-tenths tons in
the environs of Durango in Mexico. In the east-
ern part of Asia, not far from the source of the

COMPOSITION OF AEROLITES. 225

Yellow River, there is a mass about forty feet in
height, according to the statement of Abel Remu-
sat. The Mongols call it the Rock of the Pole,
and say that it fell after the appearance of a
meteor. The only aerolite of this character, the
celestial origin of which is ascertained, fell near
Agram, in Dalmatia, on the 26th of May, 1Y51.

The most remarkable aerolite which the
mineralogical galleries of the French Museum
possess, is that of Privas, in Ardeche. It fell on
June 5, 1821, weighs two hundred and two and
four-tenths pounds, and buried itself more than
seven inches in the ground. An approximative
calculation, based upon data collected since they
have been observed with greater care, estimates
the number of meteoric descents at about six
hundred annually. The rocks of native iron,
resting on the soil in different parts of the globe,
and not homogeneous with the surrounding land,
are also probably aerolites.

Usually, the aerolites which people have suc-
ceeded in touching at the moment of their fall,
were very hot, but one was recently noted in the
Punjaub that froze the hands of those who at-
tempted to pick it up. It is easy to explain this
low temperature, if we admit that these bodies
have traversed the interplanetary spaces, where,

226 METEORS ATVTD METEORIC PHENOMENA.

according to some physiologists, the temperature
descends to one hundred and forty degrees. The
passage through our atmosphere heats, as we have
seen, only the surface of the meteoric mass, which,
in breaking, lets fall fragments of the central part,
that retains its very low temperature. In metallic
aerolites, the transmission of the enormous ex-
ternal heat is very rapid, and they often reach the
earth in the condition of red-hot balls.

PERIODICAL DISPLAYS.

When the celestial origin of these meteoric
bodies was, at last, recognized, it was thought
that they might come from the moon, and that
they were the product of its volcanoes. It was
calculated that, in order to cause them to pass be-
yond the limit of our satellite's attraction, a force
double that which projects the ball from our
heaviest cannon would suffice. They would then
come near enough to revolve around the earth,
and sometimes be drawn to its surface. But this
explanation did not account for the new appear-
ances that we are about to mention, and which
have led to a more general hypothesis. These
appearances embrace the flood of meteors which
illuminates the heavens at diiferent periods of the
year, and of which the displays offer a remarkable

PERIODICAL DISPLAYS. 227

element of periodicity. Olmstead and Palmer
have given descriptions of the enormous shower
of falling-stars which they saw in America during
the night between the 12th and 13th of Novem-
ber, 1833. The meteors fell like snow-flakes, and,
in the lapse of nine hours, the number seen from
one station was estimated at more than two hun-
dred thousand. They shone with various colors ;
fire-balls of all dimensions were mingled with
them, and in the depth of the firmament light
phosphorescent traces were detected. In 1799, at
the same period of the year, Humboldt had wit-
nessed a phenomenon nearly as brilliant, at Cu-
mana. In 1823, and again in 1832, a similar one
was seen in Europe, and it was then observed
regularly every year until 1842. But from that
year the date of its appearance became displaced
and pushed on toward the close of October. At
the same time, the phenomenon had greatly di-
minished, and had even entirely disappeared.

Such was not the case in reference to another
date, which is kept up with great precision. It is
the 10th of August, or rather it covers the space
from the 9th until the llth of that month. Un-
questionable documents establish the fact that the
Chinese astronomers observed showers of shooting-
stars more than ten centuries ago, at the same

228 METEORS AND METEORIC PHENOMENA.

periodical date, and for a long series of years. In
France, the popular tradition relative to the fiery
tears of Saint Lawrence on his fete day, the 10th
of August, indicates under a legendary form the
periodical return of these showers of meteors.
M. Herrick (Arago quoting him) states that, ac-
cording to an old tradition popular in Thessaly,
in the midst of the mountainous countries that
surround Mount Pelion, the sky opens during the
night of August 6th, the festival of the Transfigu-
ration, and torches are visible through the orifice.

The most recent investigations show that, dur-
ing the greater part of our century, the phenome-
non has recurred with constant regularity, and has
been visible over the entire globe.

M. Quetelet, in a learned memoir on the
" shooting-stars of the 10th of August period, in
1863," reproduces the following letter from Sir
John Herschel :

"As for my opinion concerning these enig-
matical phenomena (that is to say, so far as the
question of their origin inside or outside of our
atmosphere goes), I could not but admit the ne-
cessity of attributing them to a cosmic origin.
Otherwise, I can see no explanation, in the least
degree admissible in any other quarter, of the
persistence from year to year of the same point of

PERIODICAL DISPLAYS. 229

radiation in contrast with others, nor of the regu-
lar recurrence on the same day of the year (Au-
gust 10th), unless by the earth meeting with a
belt of * something ' revolving around the sun.
Without doubt this explanation leaves something
yet to be explained, but it satisfies the two grand
conditions of the problem, and these two grand
conditions are the most striking. As to their
great elevation above the earth, it leads us to sus-
pect the existence of a kind of atmosphere higher
up than the aerial atmosphere, lighter, and, so to
speak, more igneous than our own."

M. Quetelet's important work, entitled " Phy-
sique du Globe," published in 1861, designates
these two atmospheric strata of different consist-
ency as the movable atmosphere, subject to varia-
tions of all kinds, and the immovable atmosphere,
of very feeble density, which remains in a condi-
tion of relative stability, or fixedness. " This up-
per atmosphere, favorable to the combustion and
to the brilliance of the shooting-stars, would not
necessarily be of the same nature and the same
composition as the lower atmosphere in which we
live."

M. Quetelet also calls attention to the fact,
that the very existence of the shooting-stars natu-
rally leads to the admission that the height of the

230 METEORS AND METEORIC PHENOMENA.

atmosphere must be at least three or four times
what it is now supposed to be.

OBSCURATION OF THE SUN.

" The sun's disk," says Arago, in his " Popular
Astronomy," tinder the head of Cosmic Meteors,
" is sometimes obscured for a few moments, and its
light becomes enfeebled to such a degree that the
stars may be seen at noonday. Humboldt recalls
the circumstance that a phenomenon of this kind,
which could not be ascribed either to fog or to
volcanic cinders, took place in 1547, about the time
of the disastrous battle of Muhlberg, and lasted
three days. Kepler was disposed to trace the
cause of it to the interposition of a materia comet-
ica, or such matter as composes the train of com-
ets, or to a black cloud which sooty emanations
from the sun had contributed to form. Chladni
and Schnurrer attributed it to the passage of me-
teoric masses over the disk of the sun, like the
phenomena of this kind that occurred in 1090 and
1208, although they were of shorter duration, the
first one lasting three and the second six hours
only.

"Messier relates that, on the 17th of June,
1777, about noon, he saw a prodigious number of
black globules pass before the sun. Did not these

THE BELT OF METEORITES. 231

globules form part of one of the rings of asteroids
of which all observations of cosmic meteors tend
to make us admit the existence ? Two other ob-
scurations of the sun — that in the beginning of
February, 1106, and that of May 12, 1706, dur-
ing which, about ten o'clock in the morning, the
darkness became such that the bats began to fly
about — seem likewise inexplicable by any other
theory."

THE BELT OF METEORITES.

According to M. Faye, the meteoric display
of November, and that of several other months,
may be connected in the following manner with
the one seen in August : The earth, in its passage
through the belt of unknown bodies revolving
around the sun, carries along with it, by its pow-
er of attraction, a great number of those bodies,
which thenceforth become her veritable satellites.
This collection burns in the atmosphere, in the
course of the year, and precipitates itself upon our
planet's surface. During their circulation in our
orbit some of these meteorites may pass singly,
like those that are seen every evening. Others,
assembled in different groups, approach or recede,
according to their position in the orbit that they
follow, and occasion the displays of November

232 METEORS AND METEORIC PHENOMENA.

and other times whose periodicity is kept up
during only a limited number of years. This hy-
pothesis would explain the appearance of swarms
of satellites seen in a single quarter of the
heavens.

The ingenious opinions which we have just
summed up may enable the reader to judge of the
lively interest that attaches, at the present time,
to what M. Faye calls " the mystery of the shoot-
ing-stars." Scarcely the first veil that enshrouded
it has yet fallen, indeed ; but observers multiply
in number and combine their efforts, and learned
men are uniting their labors, sustained by the
profound feeling that inspired the following pages
from the pen of Humboldt :

" To see motion rise suddenly in the midst of
the calm of night, and for a moment disturb the
tranquil radiance of the starry vault; to follow
with the eye the meteor which, in falling, traces
its luminous trajectory athwart the firmament —
is not this to have one's thoughts ascend, straight-
way, to those infinite spaces which are filled
everywhere with matter, and everywhere vivified
with movement? Of what consequence is the
diminutive size of these meteors in a system
where, along with the enormous volume of the
sun, one finds atoms as small as Ceres, or as the

THE BELT OF METEORITES. 233

first satellite of the planet Saturn ? What matters
their sudden disappearance when a phenomenon
of another order, the extinction of those stars that
shone all at once in Cassiopeia, in the Swan, and
in Serpentarius, has already forced us to admit
that there may exist in the celestial spaces other
stars than those that we always see there ? We
know the fact, now, that shooting-stars are aggre-
gations of matter, veritable asteroids, that circulate
around the sun, which, like comets, sweep across
the orbits of the larger planets, and shine near our
atmosphere, or, at least, in its highest strata.

" Isolated upon our planet from all parts of the
creation which the limits of our atmosphere do not
embrace, we are not in communication with the
celestial bodies, excepting by the rays of heat and
light, and by that mysterious attraction which
those distant masses exert upon our globe, our
seas, and even the beds of air that surround us.
Eut, if aerolites and shooting - stars be really
planetary asteroids, the method of communication
changes : it becomes more direct, and, in some
sort, assumes a material shape. In fact, we no
longer have to deal with those far remote bodies,
the action of which, upon the earth, is limited to
the production of luminous or calorific vibrations,
or motions in accordance with the laws of a re-

234: METEORS AND METEORIC PHENOMENA.

ciprocal attraction of gravitation. We now have
before our contemplation material bodies, which,
abandoning the celestial spaces, traverse our at-
mosphere, and dash against the earth, and thence-
forth form a portion of it. Such is the only cos-
mical event that can put our planet in contact
with the other parts of the universe. Accustomed
as we are to know things placed outside of our
globe only through the medium of measurement,
calculation, and reasoning, we are now surprised
at being able to touch them, weigh them, and
analyze them. It is thus that science brings the
secret springs of the imagination and the living
forces of the mind into play in our souls, while the
vulgar throng behold in these phenomena but
sparks that flash up and then die out, and in these
black stones, that fall with a crash from the bosom
of the clouds, nothing but the coarse product of
some convulsion of Nature."

CHAPTEE X.

DUST IN THE ATMOSPHERE.— DRY FOGS.

Cosmic Dust.— Volcanic Ashes.— The Sands of the Deserts.— The Red
Mists of Cape Verde.— Showers of Manure.— Dry Fogs.

COSMIC DUST.

A COSMIC origin must be assigned to a great
deal of the dust that falls from the atmosphere.
Not only have aerolites of very slight consistency
been picked up, but many savants think that the
appearance of bolides is often due to bodies of
dusty consistency traversing the celestial spaces.
This hypothesis was announced, in 1849, by M.
Heiss, in his work upon periodical shooting-stars.
" It is easily understood," says M. Haidinger, in
an interesting memoir, " that agglomerations of
dusty matter, collected in a globular form, and
passing through the upper strata of the atmos-
phere, first excite, in their totality, certain lumi-
nous phenomena. But they must soon be resolved

236 METEORS AND METEORIC PHENOMENA.

again into dust, leaving nothing in existence that
could determine a development of light. We
would here recall the fact that, according to M.
Julius Schmidt, the most luminous meteors seem
to blaze up at more considerable heights, while
those of less intense brightness belong to less ele-
vated regions. The different modes of the diffu-
sion of their light may be attributed to the greater
or less volume of the particles. The smallest
grains of dust emit light so soon as they reach the
upper strata, and die out just as quickly, because,
after a short course, they are dispersed by the re-
sistance of the atmosphere. The less diffused
particles make a longer run, but they also die
out, generally at considerable heights."

The great meteors that descend to the lower
strata, and are seen to have a rotary movement,
and disappear without causing a fall of aerolites,
may be considered as relatively voluminous ag-
glomerations of dusty matter. They frequently
leave behind them luminous trains that last
for some time. Admiral Krusenstern, in his
voyage around the world, saw the broad track of
a bolide shining for more than an hour, without
seeming to change place to any perceptible de-
gree. We have mentioned the clouds that are seen
during the daytime in the track of meteors. Mr.

COSMIC DUST. 237

B. Y. Marsh, describing the one that appeared on
the 15th of November, 1859, in a part of America,
says that it left a column of smoke about a thou-
sand feet in diameter, the base of which was at an
elevation of nearly eight thousand. These ap-
pearances can be explained only by supposing the
presence of immense masses of dusty matter.

M. von Reichenbach, who has paid much at-
tention to aerolites, has published some remark-
able studies in reference to their relations with
comets, which he considers as being composed of
the same material reduced to very minute parti-
cles widely separated from each other. The con-
densation of these clouds of cosmic dust at differ-
ent degrees, seemed to him to explain the granu-
lated appearance observed in meteoric stones, and
even in masses of iron which he succeeded in
separating into globules.

The fall of dust, the matter of which was iden-
tical with that of aerolites, has been ascertained,
beyond a doubt, by recent chemical analysis, as
well as by quite a number of historical accounts.
Pliny affirms that " a fire was seen to fall from
heaven in a shower of blood." This fire must
have been the light emanating from a bolide, and
the blood a re(j (lust mixed with the rain. In

Procopius, there is mention made of a great fall
12

238 METEORS AND METEORIC PHENOMENA.

of black dust in the environs of Constantinople, in
the year 472 ; it must have accompanied a lumi-
nous meteor, since, according to the historian,
" the heavens seemed on fire.'r

Arago has compiled many similar facts in his
" Popular Astronomy." He mentions the fall of
red and blackish matter that took place at Yerde,
in Hanover, and was accompanied by a globe of
fire and violent detonations. This matter burned
the wood-work upon which it fell. On March 14,
1813, red dust and red snow fell in Calabria, Tus-
cany, and Friuli, and, at the same time, a great
noise, and the falling of stones, were heard at
Cutro. Sementini found, in several specimens of
this dust, the ordinary chemical composition of
aerolites.

In November, 1819, a black rain and snow fell
at Montreal, and in the northern part of the United
States. This fall was accompanied by an extraor-
dinary darkening of the sky, shocks similar to
those felt during an earthquake, detonations, and
very powerful flashes of lightning. Some persons
have attributed these phenomena to the conflagra-
tion of forests, but the noise, the shocks, and all
the circumstances, go to show that it was a real
meteor.

The American sea-captain Callam reports a

VOLCANIC ASHES. 239

curious observation made by Mm. His ship was
in the Indian Ocean, to the southward of Java,
when a shower of very small stones fell suddenly
on the deck, without the occurrence of any other
phenomenon to explain this odd circumstance.
He picked up several fragments, and Commander
Maury, to whom he gave them on his return to
America, sent them to M. Ehrenberg, who, by the
aid of a powerful microscope, ascertained that the
matter of these fragments had originally been
liquid, but had been solidified during its descent.
It offered complete resemblance to the residue re-
sulting from the combustion of a steel wire burned
in a flask full of oxygen ; and this leads us to in-
fer that the fragments were drops of water falling
from the incandescent surface of an aerolite which
had passed above the ship.

VOLCANIC ASHES.

Clouds of dust rise from the bosom of the
earth, also, that frequently spread through a great
breadth of atmosphere. These are the volcanic
ashes, which, sometimes scattered by the winds,
and sometimes falling in dense showers on the
soil, bury whole cities beneath them. The follow-
ing narrative of the most memorable of these ca-
tastrophes will give an idea of the phenomenon :

24:0 METEORS AND METEORIC PHENOMENA.

" In T9, under the Emperor Titus, Pliny the
naturalist was in command of the Roman fleet,
near Cape Misenum, westward of Naples. His
sister, the mother of Pliny the Younger, drew his
attention one evening to a cloud of extraordi-
nary size and shape. This cloud, after rising in a
vertical column, expanded at the top and assumed
the appearance of a spreading pine-tree. Pliny
ordered out a boat and went rapidly toward Ve-
suvius, from which, as was soon perceived, this
cloud, or rather this smoke, ascended. The dense
shower of cinders, pumice-stone, and fragments
of rock, hurled from the crater, was already terri-
fying the neighboring country-people, but the
naturalist advanced boldly to the scene of danger.
Near Stabia, he passed the night in a villa, and,
being much fatigued, slept so profoundly that his
breathing could be heard outside. When he
awoke, it was only with some difficulty that he
could leave the house, the cinders having nearly
choked up the doorway. At the break of day,
which the eruption rendered nearly as dark as
night, he tried to advance nearer to the moun-
tain, in order to observe the phenomenon. The
flames and sulphurous vapors, that made every-
body else recoil, only stimulated his ardent cour-
age. But, soon afterward, he was seen striving to

VOLCANIC ASHES. 241

rise from the spot where he had sat down for a
moment, and then suddenly fall, struck with apo-
plexy or suffocated by the fumes."

It may be remembered that during this vio-
lent eruption the cities of Pompeii, Stabia, and
Herculaneum, disappeared, the first two under a
mass of cinders and scoriae, and the latter beneath
the lava. They remained thus buried for seven-
teen hundred years, and their exact site was no
longer remembered, when, by accident, they were
again discovered."

Captain Basil Hall reports the following: —
" On the 1st of May, 1812, after some violent
detonations, that terrified the inhabitants of Bar-
badoes, a black cloud was descried, seaward, upon
the northern horizon. Ere long, it covered the
whole sky, which had just been emerging from the
shadows of morning twilight. At length, the
darkness became such that it was impossible, in-
doors, to tell where the windows were, while, in
the open air, many persons could not see either
the trees near which they were passing, the out-
lines of the neighboring houses, or even white
handkerchiefs placed a few inches from theii
eyes. This phenomenon was occasioned by the
fall of an enormous quantity of volcanic dust issu-
ing from a crater on the Isle of St. Yincent, and

242 METEORS AND METEORIC PHENOMENA.

containing, according to the analysis made by Dr.
Thompson, ninety-one parts of silex and alumi-
num, eight of calcareous matter, and one of oxide
of iron. This new kind of rain, and the profound
darkness it occasioned, did not cease entirely un-
til between noon .and one o'clock; but, several
times during the morning, there were noticed, by
the aid of a lantern, showers, so to speak, in which
the dust fell in greater abundance. Trees whose
wood was flexible bent beneath the burden, and
the noise that the branches of other trees made
in breaking contrasted in a very striking manner
with the calmness of the atmosphere. The su-
gar-canes were completely beaten down, and the
whole island was covered with a bed of greenish
ashes an inch in depth."

The Isle of St. Yincent is situated about one
hundred and six miles to the west of Barba-
does, and Arago inferred, from the passage of vol-
canic ashes to such a distance, that there is an
upper current blowing in a direction counter to
the trade-winds, which in these regions, and par-
ticularly during the months of April and May,
blow uniformly from the eastward with a slight de-
viation to the north. We must, then, admit that
the volcano on St. Yincent had hurled the immense
quantity of ashes, which fell upon Barbadoes and

THE DESERT SANDS. 243

the adjacent seas, to a height where not only the
trade-winds ceased to be felt, but even where a
current diametrically the reverse of them pre-
vailed.

When dispersed by the winds, volcanic ashes
sometimes travel very great distances. Those
that issued from Vesuvius were found at Con-
stantinople. In the formidable eruption of Tom-
boro, a volcano of the island of Sumbawa, which
took place in April, 1815, the ashes went as far as
Java, Macassar, and Batavia. They even fell at
Bencoolen, in Sumatra, more than nine hundred
and thirty-one miles distant.

THE DESERT SANDS.

On the deserts, the winds carry great masses
of sand, which sometimes cause terrible catastro-
phes. The soil is composed of light sand, which
the storm tosses as it does the billows of the sea.
Enormous whirlwinds bury whole caravans, and
frequently it is by the bones found in the sandy
beds that the way across these vast solitudes is
recognized.

One characteristic feature of our globe is the
line of deserts that traverses Africa and 'Asia,
forming a zone of four hundred leagues in diam-
eter at some points, with a total length of nearly

244 METEORS AND METEORIC PHENOMENA.

three thousand leagues from the Senegal to the
Mle, and from Arabia to Mongolia. In certain
localities of Sahara, and in the Desert of Gobi, the
bottom of ancient seas has been distinctly recog-
nized ; and one may readily conceive of an epoch
when the series of these internal sheets of water,
the Mediterranean, the Black Sea, the Caspian,
the Aral, and all the lakes of the steppes as far as
Lake Baikal, was repeated in a more southern but
parallel region more exposed to drought.

" This prolongation of continuity in the
deserts," says Jean Eeynaud, developing this
hypothesis, " might be very readily explained by
one of the great laws of the atmosphere, viz. : the
habitual movement of the air from west to east in
the temperate zones. Supposing separate and
distinct aggregations of sand to have existed
originally, and to have been arranged like the
present great desert, along a line not very widely
diverging from the parallel of the equator, the
sand being constantly thrown toward the east by
the wind, would, at length, necessarily have
formed along the whole line, commencing at
its point of departure, lengthened sandy trains
joining the other trains behind it, and thus have
united all the primitive deserts in one single waste.
This displacement of the deserts, this continual

THE DESERT SANDS. 24:5

extension of their limits toward the east, in the
temperate zones, at least, is an ascertained fact.
Nature has not fixed the sand as she has the sea.
God did not say to the desert when He created it,
'Thus far shalt thou go, and no farther.' It
is not Egypt, at all events, that would contradict
our assertion. The wind drives the sand of Sa-
hara over that country, and has already scattered
enough upon it to almost entirely cover the upper
tracts of the valley of the Kile. In a few centuries
more, Upper Egypt will be completely buried;
the sands will accumulate at the foot of the
mountains that separate the region in question
from the Red Sea, until, at length attaining their
level, they may continue their onward march, and
extend over AraBia the continuous mantle of the
desert.

" The districts of the Thebaid, once the most
densely-peopled and most flourishing on earth,
now belong to the sandy waste. The temples
rear their desolate capitals above the sand as
though above the waters of a deluge; and the
sphinxes, like those fossil creatures of the antedi-
luvian world, of which no traces are now discov-
ered, excepting in the bosom of the subterranean
strata, repose peacefully in its depths."

To this moving picture of the progressive in-

24:6 METEORS AND METEOEIO PHENOMENA.

vasion of the deserts, Jean Keynaud adds the
following considerations: "Will the trip across
these inhospitable solitudes ever become more
prompt and easy than it is now ? Has the indus-
try of civilized nations any thing to add to what
the experience of the nomadic tribes who haunt
the desert, has invented for this purpose ? In my
mind, the reply to this question is npt doubtful,
so great does the scope of human power appear to
me ; but, at the same time, I recognize the fact
that such a task is beyond its strength. We have
subjected the ocean by means of steam, we may
subdue the mountains when we will by the aid
of inclined railroads, but how shall we ever make
the untamable elements of the desert submit ? It
is a rude problem to solve. Its solution assuredly
cannot be directly approached, and, besides, the
time has not yet come. But it suffices to state
the question, in order to catch a glimpse, at once,
of the full majesty of the desert. A force which
has broken down so many other barriers has not
even a hold on this one. All that we have to go
upon, in attempting to speak with certainty on
this subject, for the honor of man, is, that the en-
gineer now knows how to fix and confine the mov-
ing sands by covering their edges with sufficient
plantations of trees ; that the agriculturist, by the

THE DESERT SANDS. 247

aid of irrigation, succeeds little by little in culti-
vating and fertilizing the most arid waste ; and
finally, that, in countries the most remote from
river-courses, the miner can, like Moses in the
desert, by striking the rocks with his iron rod,
make springs leap from them, and thus give birth,
in plains the most destitute of all the gifts of Na-
ture, to verdant oases. But from these attempts,
made on a small scale in some districts, to the
general cultivation of Sahara, and to the establish-
ment of well-made roads across a grassy surface,
where all now is sand, there is a lapse of time to
come as prolonged as the imagination can con-
ceive."

Let us here add that the recent discovery of
an immense watery deposit extending under the
Algerian part of Sahara, admits the hope of at
least a slow transformation. At every spot where
the subterranean sheet bursts forth, forests of palm-
trees, that form the oases, quickly spring up. The
oasis of Ouargla, which possesses a great number
of Artesian wells, counts as many as one hundred
and fifty thousand palm-trees, that, according to
the Arab saying, live with " their feet in the
water, and their heads in the fire." These still
favor the cultivation of the ground, which is not
possible excepting beneath their sheltering shade.

24:8 METEOKS AND METEOEIC PHENOMENA.

Navigators, in following the coast of Africa,
often encounter winds to which their burning
heat, an extreme dry ness, and the presence of sand,
give a peculiar character, that must be attributed
to their- passing over the desert. These winds are
designated according to locality, as the simoom,
the sirocco, the khamsin, the harmattan, etc.
During the continuance of the simoom, which
often blows in a whirlwind, a temperature of fifty
degrees has been noted in the shade. The sirocco
reaches the coasts of Italy, and carries the sand
along with it. The Jchamsin, which is of very
elevated temperature^ owes it name, meaning fifty,
to its long duration. It precedes and follows the
equinox for twenty-five days. The harmattan
blows upon the coast of Guinea, and is always
accompanied by a peculiar kind of fog. " This
fog," says Arago, " is so dense as to afford passage
to but few rays of the sun at noonday, and al-
ways rises when the harmattan is blowing. The
particles of which it is formed deposit themselves
on the sod, on the leaves of the trees, and on the
skin of the negroes, in such fashion that every
thing for the time being looks white. The na-
ture of these particles is unknown. All that we
do know about them is, that the wind carries
them but a very little distance out upon the ocean

THE RED FOGS AT CAPE VERDE. 249

away from the coasts. Only one league at sea
the fog is much attenuated, and at three leagues
there is not a trace of it to be seen, although the
harmattan makes itself felt there in full force."

THE RED FOGS AT CAPE VERDE.

M. Ehrenberg believes that the name of dark
or gloomy sea, given to the Atlantic by the an-
cients, took its rise in the phenomenon observed
after the mariner has issued forth from the Straits
of Gibraltar and is drawing near to the waters
by Cape Yerde. At the approach of the equi-
noxes, and during an interval that varies from
thirty to forty days, there falls a very fine red
powder that obscures the atmosphere and deposits
itself upon the rigging of vessels. This shower
of dust, known also as the red fog, extends over a
sea-surface of more than a million of square miles.

Showers of red dust have been frequently
noted, also, at different points on the Mediter-
ranean, and in Europe and Western Asia, but at
irregular epochs. Near Lyons, for instance, in
1846, there fell a quantity, estimated in all at
seven thousand two hundred quintals, on a sur-
face of four hundred square miles. This dust is
not composed of sand and clay alone, but also of
organic substances and infusoria, which a powerful

250 METEORS AND METEORIC PHENOMENA.

microscope renders quite visible. A sort of worm,
which, along with the clay, gives color to the mix-
ture, is so small that it requires nearly two mill-
ions of these animalcula to fill the space of a
cubic inch. One thing especially remarkable is,
that, in the many specimens examined by M.
Ehrenberg, and collected on the Atlantic as well
as in Europe, Asia Minor, and Syria, the same
species have always been found. The savant in
question has prepared a chart on which all the
places where this dust has fallen are marked. He
admits that the showers of blood mentioned in
history may have been confounded with this phe-
nomenon, since the fluid in question might well
be represented by the red substance above men-
tioned, when the latter is moistened with water,
and such an explanation of the legendary fact is
too obvious to be rejected.

The interesting question of the origin of these
peculiar kinds of dust then occupied his attention,
and led him to analyze a great many specimens of
the soil collected in different parts of Africa and
South America. The result showed that nowhere
on the first-named continent could species of in-
fusoria be found the same as those discovered in
the dust, while on the second they were met with
near the Orinoco and Amazon Rivers.

THE BED FOGS AT CAPE VEKDE. 251

This circumstance very forcibly struck the at-
tention of Commander Maury, who saw ,that these
dust-falls may serve to mark the extent of the cir-
cuit made by the aerial currents, just as bottles
thrown into the sea by mariners mark the sweep
of the ocean-currents.

The periodicity indicated by the appearance
of this dust at Cape Yerde has relation, according
to Maury, to the movement of oscillation north
and south of the zone of equatorial calms, a move-
ment that carries the rainy season from point to
point over the surface of America. " At the
period of the spring equinox," he says, " the val-
ley of the lower Orinoco is in its dry season ; the
marshes and plains in that region are converted
into arid deserts ; the water has, so to speak, dis-
appeared, and the trade-winds can very readily
bear away with them the dust that whirls about
on these parched savannas. Six months later, at
the autumnal equinox, the relative position of the
zones of calm and of the trade-winds has changed.
It is the greater part of the valley of the Amazon
which becomes a prey to drought and which in its
turn furnishes to the heavy breezes of that period
of the year the organic dust that we find in the
other hemisphere."

Humboldt gives us an easy comprehension of

252 METEOKS AND METEORIC PHENOMENA.

how the dust is carried up from those burning
plains : " "When, under a vertical sun and a cloud-
less sky, the grassy carpet is scorched to a cinder
and reduced to dust, the baked soil cracks open
as though it had been split by violent shocks
of earthquake. Should opposite currents of air
meet each other midway at this moment, and by
their conflicting action produce a gyrating move-
ment, the plain presents a strange spectacle to
the observer. The sand rises like a conical cloud,
the point of which scores the ground, in the
midst of the whirlwind, which is highly charged
with electricity. It might be mistaken for one
of those howling tornadoes so dreaded by the
experienced seaman. The vault of the heavens,
which seems lower down than usual, reflects only
a dull and opaline light over the plain. Sudden-
ly, the horizon seems to draw closer and space
contracts. Suspended in the cloudy atmosphere,
the red, hot dust still augments the suffocating
temperature of the air; and, instead of refresh-
ing coolness, the east wind, sweeping over the
burning soil, only brings a more blazing heat."

SHOWERS OF MANURE.

We have still to mention certain kinds of dust
that are floating continually around us, and which

SHOWERS OF MANURE. 253

the luminous ray causes to appear to us, in any
dark space, in whirlwinds of sparkling particles.

There mingle in the dust of our streets and
roads some detached remains of every thing we
use — the tiny atoms of the smoke that rises from
our hearths, as well as the floating molecules that
escape in the decomposition of organic bodies.
These materials are of great value, as learned
agriculturalists have indicated. " Perhaps," says
M. Barral, "it would be correct to say, that
the air remaining in a condition of purity equal
to that which is sometimes attained in our labo-
ratories, would strike the earth with barrenness.
Perhaps, too, it is necessary for the maintenance
of life on our planet, that a host of impurities
should be incessantly carried hither and thither,
by the winds and the storms, from the places
where they are produced to regions where germs
are waiting to be fructified."

A great number of salts (for instance, marine
salt), that are adapted to the provision of elements
necessary to vegetation, exist in rain-water, and
consequently in the atmosphere. Dalton found
one hundred and thirty-seven milligrammes of
chloride of sodium (or marine salt) per litre near
Manchester, and M. Barral has ascertained that
there are four milligrammes in the rain-water of

254 METEORS AND METEORIC PHENOMENA.

Paris. As we retire from the sea, the proportion
of salt diminishes, and every thing leads us to
infer that this substance is raised from the bil-
lows of the ocean by the great winds, and borne to-
ward the interior. Salt-rains are often mentioned
in works on meteorology, and Pliny cites several
instances. Sometimes there have been found,
with the salt, the iodine and bromine that accom-
pany it in the brine of the deep.

Particles of phosphoric matter also are often
detected in the air. They have been carried up,
no doubt, in the form of dust, from those parts
of the globe's surface where the phosphate of
lime is abundant. This dust, descending along
with the rain, contributes powerfully to the fer-
tility of the soil. Each crop of grain withdraw-
ing seventeen and a half pounds of phosphorus
per acre from the soil, and the supply yielded by
the atmosphere being much less, we may readily
comprehend why races who, like the Arabs, nev-
er manure their lands, are obliged, after having
drawn some scanty products from them, to aban-
don them for several years, until the soil shall
have reacquired the elements necessary for a new
crop. The sea, which in certain circumstances,
and particularly during tempests, becomes illu-
minated with the phosphorescent coruscations due

DRY FOGS, 255

to the presence of innumerable animacules, must
also contribute to the diffusion of phosphorus.
This substance likewise comes from the subter-
ranean putrefaction of animal matter, and dis-
perses itself in the atmosphere, above swamps and
marshes, by means of those mysterious Jack-o'-
lanterns, or Will-o'-the-wisps, that liave given rise
to so many superstitious stories.

DKY FOGS.

We mention, along with atmospheric dust, the
phenomena known as dry fogs, due to matter of
great tenuity, but not aqueous, suspended in the
atmosphere, the clearness of which they overcloud.
Humboldt, when on the summit of the Silla, found
himself enveloped in a dense cloud that concealed
the nearest objects from his view, without his
clothing being dampened in the least degree. At
the same time, the hygrometer marked the highest
degree of dryness.

In Switzerland, the name of hale is given to a
sort of smoke that accompanies the north wind
during the summer, and extends around the hori-
zon, shutting out the Alps from view. It is some-
times gray, sometimes red or russet-colored, and
the sun when seen through it has a sombre, red-
dened hue. The callina is a similar exhalation

256 METEORS AND METEORIC PHENOMENA.

in Spain, which gives the sky a leaden or livid
tinge.

In the north of Germany, certain dry fogs are
but real smoke produced in the fields by the
combustion of turf and other vegetable matter.
Broad surfaces sometimes take fire spontaneously
in the peat-bogs, and the quantity of combustible
material consumed often amounts to millions of
pounds. It has been noted that the wind always
blows from the direction of the turf-beds when
there is a dry fog. " The dense fog of 1834
came," says Kaemtz, " from the combustion of the
peat-beds, and from the many fires that marked
the year. When it was noticed in the Hartz
Mountains, toward the end of May, there were
fires in the peat-beds in the neighborhood of
Basle and Orleans. Thus, to mention one par-
ticular case, the peat-beds of Dachau, in Bavaria,
burned to a depth of more than nine feet, and the
fire propagated itself beneath ditches full of water.
In the environs of Minister, and in Hanover, many
peat-beds were consumed. Later, in July, there
were terrible conflagrations in the forests and
turf-pits near Berlin, in Silesia, in Sweden, and in
Russia, and the drought favored the propagation
of these fires and the drifting of the smoke."

M. le Yerrier has given a description of a

DRY FOGS. 257

singular cloud which is noticed daily at Paris.
It comes from the smoke of the forges situated in
the direction of the Maison Blanche : " The spec-
tacle," says he, " is really curious to see. From
the top of the chimney issues a cone as black as
ink. This cone spreads open, little by little,
gains distance over the city of Paris, and passes
beyond it, sometimes to the north and sometimes
to the south of the Observatory. When it passes
to the northward, we follow it with our gaze as
far as Gentilly. No sunshine falls at that mo-
ment on a large part of Paris. At least such is
what the inhabitants think; the sun is really
hidden by the smoke of these forges, while to the
northward it is brilliant."

Sometimes immense swarms of insects have
presented the appearance of a collection of clouds :
"On Tuesday, the 7th of September, in very
calm weather, workmen employed in replanting
a part of the Esperou Mountain witnessed an ex-
traordinary phenomenon, one unexampled, in fact,
in those regions. At two o'clock in the after-
noon, a dull and monotonous noise, almost analo-
gous to that produced by a distant thunder-storm,
fixed their attention upon a dense mist that was
sweeping over a small hill about six miles in ad-
vance of them. As the air was very calm, they

258 METEORS AND METEORIC PHENOMENA.

were astonished at this humming sound, and their
first idea was of a fire in the direction of Esperou ;
but, determined to ascertain the real reason of so
intense a mist, they were no little surprised when,
as they moved toward it, they discovered that it
was an immense column of gnats, the length of
the cloud being some five thousand feet, with a
perpendicular depth of from one hundred to two
hundred feet. This column of insects was mov-
ing from east to west. An eye-witness, a forest-
keeper who was superintending the workmen in
the woodland, has furnished us these particulars."
An extraordinary dry fog extended, in 1783,
over the whole surface of Europe, and a part of
Asia. Its density was such that, in some places,
objects less than a mile distant could not be dis-
guished, and people could look at the noonday
sun without being dazzled. This phenomenon
was first remarked at Copenhagen on the 9th of
May, after a succession of fine days. At other
places it was preceded by wind and rain. It
was seen, on the 6th of June, at La Rochelle ; at
Dijon on the 14th, and on the 16th at Manheim
and at Rome. It appeared on the 19th in the
Netherlands ; on the 22d, in Norway ; on the
23d, on the Saint Gothard and in Hungary ; tow-
ard the close of June, in Syria ; and by the 1st of

DRY FOGS. 259

July on the tops of the Altai Mountains. Its du-
ration varied at different places ; and it was inter-
rupted, here and there, by fine days. This fog
had one remarkable peculiarity during the night-
time : it was phosphorescent, and the light it
yielded was sufficient to read by.

A great many conjectures have been offered
as to the cause of this phenomenon. Yan Swin-
den and Toaldo think it attributable to the earth-
quakes and volcanic eruptions which in that same
year disturbed Calabria and Iceland. From the
month of February until the end of March, there
were terrible commotions of the earth's surface in
Calabria ; mountains were shattered, an immense
number of chasms opened and emitted smoke, and
more than one hundred thousand human beings
perished under the ruins of the fallen cities.

The eruptions commenced in Iceland on the
1st of June. Seventeen villages were swallowed
up, and the lava of Hecla consumed a great
quantity of vegetable matter. There were also
many turf-beds in combustion throughout Europe.
But none of these explanations sufficed. Frank-
lin, at last, put forward an hypothesis that prob-
ably comes near to the truth. According to his
idea, an immense fiery meteor had been burning
in the upper regions of the atmosphere, and
13

260 METEOKS AND METEOEIO PHENOMENA.

the strange fog was due to a vapor of cosmic
origin.

A similar phenomenon was observed in the
month of August, 1831, in a part of Europe, upon
the north coast of Africa, and in the United
States. It diminished the light of day, and, in
the night-time, diffused a phosphorescent radi-
ance. No comet having been discovered at the
epochs when these dry mists appeared, they could
not be considered the product of the cometary
vapors that the earth, according to Arago, has to
traverse several times in the course of a century,
and which must be the origin of the atmospheric
phenomena that are sometimes visible, but more
frequently pass unperceived, owing to the exces-
sive tenuity of the matter that composes the tails
of comets.

CHAPTER XI.

PROGNOSTICS OF THE WEATHER.

Progress of Meteorology. — Foretelling the Weather. — Orpheus, Ho.
mer, Hesiod, Virgil.— Prognostics furnished hy Animals.— Prognos-
tics from Plants, and from the State of the Sky.— Characters of the
Seasons and of Future Years.— Shooting-Stars.— Influence of the
Moon.

THE PROGRESS OF METEOROLOGY.

HIPPOCRATES, in his "Treatise on Atmos-
pheres, Waters, and Places," and Aristotle, in his
"Meteorologies," submitted the observation of
atmospheric phenomena to experimental meth-
ods, and collated the first elements of a positive
meteorology. The progress of science, notwith-
standing the living impulse given by these two
great minds, and in spite of the labors of The-
ophrastus, Pliny, and Seneca, was very slow un-
til the middle ages, when the discoveries of Avi-
cenna, of Albert le Grand, and Roger Bacon,
caused it to take a new step in advance. But it
is to the remarkable progress of the physical

262 METEOES AND METEORIC PHENOMENA.

sciences, to Galileo, Porta, Descartes, Pascal,
Huygens, and Mariotte, that meteorology owes
the discoveries that have secured its development.

Among the learned men whose labors have,
more recently, given a powerful flight to this
most important branch of science, we may mention
Humboldt and Maury, to whom we are indebted
for the increased number of observations which,
on land and sea, are now gathering so much pre-
cious information. It is also to their persever-
ing initiative that we owe the large developments
through which meteorology is now entering the
path of practical usefulness, and, by its numer-
ous applications to agriculture, navigation, public
health, geology, etc., enhancing the universal in-
terest its researches have always awakened.

If we bring together the superstitious notions
of the past, and the teachings of contemporane-
ous science, we see that it is to the love of the
marvellous, to our common predilection for the
unknown, as much as to our primitive ignorance,
that we must attribute the appeal to the super-
natural made by the ancients upon nearly all
occasions when they tried to account for atmos-
pheric and terrestrial phenomena. But this ten-
dency, which, even through so many errors, has
after all guided us toward the truth, still exists in

THE PROGRESS OF METEOROLOGY. 263

us, and we must reflect that it will never cease to
intervene in our moral and intellectual progress.
Directed, in our day, toward regions less obscure,
toward truths more luminous and imposing, it
will lead us to a higher interpretation of Divine
management, and a more exact recognition of the
fundamental laws the sway of which beneficently
maintains " order in the universe and magnifi-
cence in order," as Humboldt has grandly said in
his "Cosmos."

Notwithstanding the favorable direction im-
parted to meteorology by the labors of several cel-
ebrated swvants, this science is still far from ap-
proaching the perfection of the other natural
sciences. It is made up of multiple and variable
phenomena, which are further complicated by a
host of circumstances, from the influence of which
it is impossible to separate them, and which are
modified to an endless extent by climate, local ar-
rangement, the configuration of places and sites,
and the nature, the elevation, or the depression
of the soil. Thus, it is only by multiplying our
observations, by repeating them incessantly in
different places, that we can reach the point where
we can shape them into general laws, of which
we may catch a glimpse in the general totality
of the phenomena, but whose application escapes

264: METEORS AND METEORIC PHENOMENA.

us under particular circumstances. Should we
ever succeed in reducing the phenomena of meteor-
ology to a small number of fundamental laws, we
may, perhaps, some day get far enough on to fore-
tell the intensity of the seasons with a certain de-
gree of probability. Without mentioning all the
advantages that would result from this, who, we
may ask, would question the importance of in-
formation that would direct the cultivator how
to combine his operations in accordance with
the weather that would favor or retard them ?
But man is far from having attained such a de-
gree of perfection as this. Nevertheless, we should
not despair of yet accomplishing it. Who will
venture to lay down limits to science ? The hu-
man mind has already unveiled enough of Nature's
secrets to let us hope that we may surprise a few
more of them.

This correct appreciation of the services that
meteorology is called upon to render, and of the ne-
cessity of the numerous observations which alone
can give it a secure foundation, points out at once
the end to be reached, and the means of reaching
it. But while, for most of the other sciences, the
observations to be collected are nearly always
either beyond our reach, or surrounded by diffi-
culties that confine them within the circle of a

ORPHEUS, HOMER, HESIOD, VIRGIL. 265

few learned men, in meteorology, on the con-
trary, any one may, by bringing to bear a little
perseverance, acquire knowledge enough to recog-
nize the weather-signs to a useful degree.

ORPHEUS, HOMER, HESIOD, VIRGIL.

From the first, man has found himself sub-
jected, either directly or indirectly, to the influ-
ence of atmospheric phenomena. Exposed to the
inclemencies of the weather, he not merely had to
seek shelter in a substantial dwelling, but to direct
his attention to the work of discovering before-
hand the perturbations that he might subsequently
have to endure.

The connection between these disturbances of
the air, the variableness of the seasons, and the
production of the fruits of the earth, was, more-
over, narrowly bound up with his material well-
being ; and we can readily understand the grati-
tude of the original tribes toward those men whose
intelligence, loftier, more active, more patient, and
more enlightened, than their own, was enabled to
seize the link between certain phenomena and
the appearance of premonitory signs. The first
priests, the first legislators, were also in the days
of antiquity the first meteorologists. We find
traces of their teachings, mingled with the stran-

266 METEORS AND METEORIC PHENOMENA.

gest superstitions, in the primitive fragments at-
tributed to Orpheus, in the poems of Homer, He-
siod, and Yirgil.

Two hymns of Orpheus invoke the favoring
breezes and the beneficent rains that fertilize the
soil:

THE CLOUDS.

" Aerial clouds, O wanderers of heaven, gen-
erators of all the fruits ! ye who hold in your
bosoms the treasures of the rain ; ye who trav-
erse the world, driven by the breath of the winds ;
thunder-striking, naming, reechoing clouds, that,
turn by turn, spread through the air a gentle mur-
mur or the howl of tempests, I now implore ye to
pour out upon the earth the favoring rains that
fructify the buds and germs ! "

THE SEASONS.

" Seasons, darling daughters of Jove and of
Themis, the most fruitful goddess of all ! ye who
load us with benefits, O richly verdant, blossom-
ing, pure, delicious seasons — seasons with varied
mingling colors, shedding abroad a fragrant breath
— ever-changing seasons, accept our pious offerings,
and send us the aid of the favoring winds that
make the harvests ripen ! "

Homer, in the " Odyssey," and Hesiod, in his

THE SEASONS. 267

" Works and Days," point out the first meteorolo-
gical observations of seamen and farmers, the pe-
riods of each season that should be preferred, in
order to conduct the tillage of the ground or avoid
the dangers of navigation with success. These
periods correspond with the courses of the stars,
and of the principal constellations, Arcturus, the
Pleiades, Orion, and Sirius, which alternately rise
and disappear, marking the advance of the seasons
in the starry heavens. Thus the " moist Pleiades,"
which, toward autumn, reascend our horizon at
the beginning of night, announce the return of the
rains. Arcturus, which brings back " spring with
its white flowers," rises in April and presides over
the first labors of the new season. Orion and
Sirius light up the stormy skies of the long
nights in winter, when the frost strips the fields,
and when the unchained tempests detain the mar-
iner in port.

Virgil, who has summed up in his " Georgics"
the whole meteorological science of his epoch,
thus recommends the indications deduced from
the movements of the stars :

" The field laborer should notice the rising of
the Bear, the Kids, and the luminous Dragon, with
the same care the skilful pilot shows when, in order
to return to his country across the stormy seas, he

268 METEORS AND METEORIC PHENOMENA.

has to face the Hellespont or the perilous Strait of
Abydos."

But to these elementary indications are added
others more important, presented by observation
of the signs by which " we learn to read a doubt-
ful sky." The course of the moon and the sun,
their different aspects, the form and color of the
clouds, the appearance of meteors, the instinctive
movement of animals, are connected with the
changes of the weather, which we may foresee
by an attentive study of the sky and the atmos-
phere. It is, moreover, evident, and Yirgil well
understood the fact, that this study required, in
order to yield all its fruits, a series of different
classes of knowledge, hardly dreamed of by an-
tiquity : . . . " Let the Muses deign to admit me
into their holy choirs ! Let them teach me the
track that is followed by the heavenly bodies;
what cause now eclipses the light of the sun, and
now the light of the moon ; what secret power all
at once swells the waters of the sea, pushes them
beyond their limits, and then hurls them back
upon themselves ; why the earth shakes on its
foundations ; why the sun seems to hasten in
winter to quench its fires in the ocean ; and
what obstacle, in summer, retards the approach
of night."

THE SEASONS. 269

If the inaccurate observation of natural phe-
nomena led to erroneous or superstitious notions
concerning the nature and the formation of me-
teors, it cannot be denied that this observation
was, likewise, the basis of the knowledge that ad-
vanced the progress of meteorology, and which,
spreading and growing more complete from age
to age, destroyed or modified the ideas of the past,
in order to substitute more rational ideas for them.
" Necessary as it is," said Cicero, " to extend and
confirm religion by the knowledge of Nature, it is
equally so to uproot superstition."

This correct and sensible view of the case,
which applies to all discoveries, to all the con-
quests of science, has an especial application to
meteorology, whose errors, mingled with those of
astrology and alchemy, have so long veiled the
providential order of things that lies concealed
under the apparent confusion of these phenom-
ena.

A summing up of the errors in question, which
were inseparable from the first researches that led
us to the truth, might have some interest for the
reader, but it would carry us too far, and we pre-
fer to point out the actual condition of the Mete-
orognosy, " which seeks to deduce future phenom-
ena from the observation of phenomena past and

270 METEORS AND METEORIC PHENOMENA.

present." We borrow this definition from the ex-
cellent treatise of M. de Gasparin upon agricul-
tural meteorology, which is about to serve us as a
guide, as we shall reproduce a few passages from
it, completing them, at the same time, by a con-
cise statement of the observations most recently
made.

METEOROLOGICAL PROGNOSTICATIONS FURNISHED BY
THE ANIMALS.

" Animated bodies receive peculiar impres-
sions that precede and announce change of
weather. Animals appear to be endowed with
an instinct in this respect, by which observers
have profited, and man himself, when perfectly
healthy, experiences sensations that enable him to
predict, almost with certainty, the meteorological
changes that are about to ensue.

" Thus, we hear distant sounds better when
there is going to be rain ; we also then see re-
mote objects more distinctly, and bad odors are
more offensive than usual.

" Swallows skim the ground in their flight ; is
it that they may feed on the worms that then
come out to the surface? Lizards hide, cats
make their toilet, birds oil their feathers, flies bite
more sharply, chickens scratch themselves and

PKOGNOSTICS FROM PLANTS. 271

roll in the dust, fish leap out of the water, and
aquatic birds flap their wings and dabble in the
ponds and brooks. Such are the results of popu-
lar observation. They have not been subjected to
any severe criticism, but they have been verified
often enough to be no longer subjected to
doubt."

PROGNOSTICS FROM PLANTS.

" Nearly all the signs indicated announce
dampness in the air, rather than the approach of
rain, for they are not seen when a storm occurs in
dry weather. Thus, the swelling of wood-work,
which renders it difficult to close doors made of
soft timber, and the contraction and tension of
cordage made of vegetable fibres, are counted
among the signs of atmospheric humidity. Rude
hygrometers have even been constructed of these
fibres. It has been noticed, also, that the flower
of the pimpernel, and the stems of the trefoil and
other plants, straighten themselves when the air is
charged with moisture. Linnaeus remarked that
the African marigold opened its flowers between
six and seven in the morning, and shut them at
four o'clock in the afternoon, in dry weather,
but that, if rain was coming, it did not open at
all in the morning ; that, when the Siberian this-

272 METEORS AND METEORIC PHENOMENA.

tie shuts its flower during the night, there is good
weather on the next day, and that if, on the con-
trary, it remains open, rain may be expected."

PROGNOSTICS FROM THE STATE OF THE SKY.

" Pallor of the sun announces rain ; it is seen,
at such times only, through an atmosphere laden
with vapors ; if the heat be stifling, that too is
a sign of rain, for one is then surrounded by
an atmosphere saturated with vapors, and more
readily heated, owing to its lack of transparency.
If the vapors be collected in clouds, the sun's
rays that pass through the latter heighten the
temperature more than they would have done in
perfectly clear weather. If the sun be clear and
brilliant, it foretells a fine day ; but, when the
sun is at its rising preceded by redness, and this
redness passes off the moment it does appear, the
sign is of rain. The presumption, then, is, that
the cold and vapor-laden air refracts the rays of
the sun — a power that it loses as it grows heated
by the rarefaction of those same vapors. The sun
setting clear and cloudless in an orange-hued sky,
is a sign of fine weather ; if the sky be red, it is
a sign of wind.

"When the sun at the horizon looks larger
than usual, the sign is of rain; the same rule

PROGNOSTICS FEOM THE STATE OF THE SKY. 273

holds good in reference to the moon. The idea
is, also, that — when the latter orb is pale, or has
concentric circles more or less dark around her
disk ; when her horns are dull at the ends ; when
a luminous halo surrounds her, leading to the ex-
pression often heard among the people in France
that the moon is bathing — there is going to be
rain. The stars also offer similar signs; their
light loses all its vividness, and they lathe when
rain is at hand.

"The sky is bluest when there is the least
vapor between it and the eye of the spectator.
Upon the mountains it assumes the color of deep
indigo. When the atmosphere becomes charged
with vapors, it loses its transparency, and the hue
of the sky becomes white, or floury, as the saying
is. This sign is unequivocal. The air ceases to be
transparent, also, through the effect of the winds,
which agitate and carry along with them such a
quantity of dust that the sky sometimes looks
reddish with it, owing to the reflection of the
light upon these solid corpuscles.

" The transparency of the air is not, however,
always changed by the approach of rain. We
have even mentioned the fact that one of the
surest signs of its coming is an unusual transpar-
ent clearness, which makes distant objects seem to

274: METEORS AND METEORIC PHENOMENA.

draw closer at such, times. Thus, in one case,
the lack of transparency in the air, and in the
other its excess, would both be signs premonitory
of rain. Facts agree with these two premises.
Let us examine the circumstances :

" 1. If the entire mass of air be very damp,
and at a temperature sufficiently elevated to have
completely dissolved the vapor; and if, at the
same time, we suppose the heat to be divided be-
tween its strata so that they remain in equilib-
rium, there is no ascending current to diminish
the transparency of the air by cooling as it as-
cends, and yet all the circumstances that can
change the temperature — the diminution of heat
as the sun declines, nocturnal radiation, and the
arrival of a cold wind — lead to rain. This con-
dition of equilibrium in the strata, joined to their
almost complete saturation with vapor, is noticed
particularly in summer, and it is then that dis-
tant objects seem near at hand.

" 2. It also happens that the higher range of
clouds will sometimes form a sort of dome above

•

our heads, and then, since we are in comparative
obscurity, the objects that are lighted up seem
nearer to us. We recall with pleasure the superb
spectacle that such an arrangement of the sky
presented to us on the summit of Mont Yentoux.

PROGNOSTICS FKOM THE STATE OF THE SKY. 275

The entire horizon was clear, but the mountain
was capped with a heavy mass of "black clouds,
which threw us into gloom. We were then ena-
bled to witness something that we never could
see again in other ascensions that we made — the
entire sweep of the eastern Pyrenees and the
coasts of the Mediterranean to where they turn
southward to regain Catalonia. A moment after-
ward, a cloud overspread the sky and a heavy
rain fell over that whole region, the atmosphere
of which was, no doubt, in the state of equilibrium
that we have described above.

" The winds also are indications of the weather
to ensue, not only through their own qualities,
but also by means of the study of the higher
winds, whose presence and direction are known
by the movement of the clouds. When the lower
wind strengthens greatly, and the clouds move in
contrary directions, on lines that make a quite
open angle, the inference is, that the lower wind
is about to yield its place to the upper one.

" Two winds of opposite qualities, succeeding
each other, often bring rain. Thus, a cold wind,
entering an atmosphere impregnated with moist-
ure by the warm wind that preceded it, will bring
about a precipitation of water ; and the same will
be the case where a damp, warm wind enters air

276 METEOBS AND METEORIC PHENOMENA.

that had been chilled by the wind that had pre-
ceded it.

" Generally, an approaching rain can be better
foreseen when the sky presents several banks, or
layers of clouds, resting one above the other. The
winds that carry with them detached masses of
clouds yield but light rains.

" Motionless clouds, lying in the quarter
whence the wind blows, bring only a continuance
of that wind ; but, if they appear in the opposite
quarter, they announce its termination.

"Clouds coming up simultaneously, yet im-
pelled by different winds, announce an early
storm.

" Clouds accumulating on the sides of moun-
tains foretell rain.

" Mists that disperse completely, without form-
ing clouds, accompany fine weather, because they
prove that the air retains the faculty of dissolving
vapor ; but many days of mist in succession lead
almost with certainty to rain."

Let us add to these signs a few collected by
Admiral Fitzroy, and quoted in his " Instructions
on the Use of the Barometer."

" The following are the signs most familiar to
navigators and farmers :

" A rosy sky at sunset, fine weather. A red

PROGNOSTICS FROM THE STATE OF THE SKY. 277

sky in the morning, bad weather or a great deal
of wind.

"A gray sky in the morning, fine weather.
If the first light of dawn appear over a bed of
clouds, wind may be looked for. If on the hori-
zon, fine weather.

" Light clouds with imperfectly-defined edges
announce fine weather and moderate breezes.
Thick clouds with well-marked edges, wind. A
deep, dark-blue sky of sombre tinge indicates
wind. A clear and brilliant-blue sky indicates
fine weather. The lighter the clouds look, the
less reason is there to anticipate wind. The more
dense, the more rolled together, twisted, and tat-
tered, they are, the stronger the wind will be. A
brilliant-yellow sky at sunset announces wind ; a
pale-yellow one, rain. According to the predom-
inance of red, yellow, or grayish tints, we can fore-
tell the condition of the weather with a very close
approximation to accuracy.

" Small clouds of an inky color portend rain.
Light clouds, moving rapidly in the direction op-
posite to dense masses, announce wind and rain.

" High clouds passing before the sun, the moon,
or the stars, in a direction opposite to that pursued
by the lower beds of clouds, or of the wind felt at
the surface of the soil, indicate a change of wind.

278 METEORS AND METEORIC PHENOMENA.

" After fine weather, the first signs of a change
are ordinarily high white clouds, in belts or in
light dappled tufts, or locks, which grow larger,
and soon form dense and sombre masses. Gener-
ally, the more remote and higher up these clouds
appear, the less abrupt the change of weather will
be, but it will be considerable.

" Soft, light, delicate tints, with clouds of de-
cided shape, indicate or accompany fine weather.
Extraordinary tints and dense clouds, with hard
outlines, indicate rain and probably a gale of
wind.

"Eemark the clouds that form on hills and
other elevated places, and cling there. If they
continue there, augment, or descend, they indicate
rain. If they, however, ascend and disperse, they
portend good weather. When sea-birds fly out
away from land in the morning, there will be fine
weather and moderate winds. If they remain
near the shore, or fly inland, gales and storms
may be expected. Many other animals are suscep-
tible to atmospheric changes, and these indica-
tions should not be neglected.

" Thus, when birds that usually fly in flocks,
swallows for instance, keep near to their nests, fly-
ing from one side to the other and skimming the
ground, the sign is of rain or wind. When do-

PROGNOSTICS FROM THE STATE OF THE SKY. 279

mestic animals seek sheltered places, when chim-
neys smoke, or when, in calm weather, the smoke
does not ascend overhead, bad weather may be
expected.

" When the sky is remarkably clear at the
horizon, and objects usually invisible are distin-
guishable from each other, or appear higher up by
refraction, there will be rain and perhaps wind.

" Extraordinary brilliance of the stars, lack of
distinctness, or apparent multiplication of the
horns of the moon, halos, and fragments of rain-
bows upon detached clouds, indicate that the wind
will increase, and that there will be rain."

M. Marie-Davy, in his "Instructions on the
Use of the Barometer," for foretelling changes of
the weather, has given the result of a comparative
examination of the meteorological charts of the
Observatory, and, in so doing, has summed up all
that is known at the present day concerning the
movements of the atmosphere on the surface of
Europe. These instructions contain very interest-
ing details relative to the advance and movement
of the whirlwinds that take place in the great
aerial current, the general direction of which ex-
erts a preponderating influence over the meteor-
ological condition of the European countries.

Other observations were recommended by the

280 METEORS AND METEORIC PHENOMENA.

International Conference held at Brussels in 1853,
on the invitation of the United States, with a
view to adopt a common system of meteorological
observations at sea. Thus, thunder-storms and
tornadoes that occur in the vicinity of the great
oceanic currents ; the drift of floating ice ; the
appearance of land birds and insects out at sea ;
showers of dust ; red or white spots that are
frequently remarked on the surface of the deep ;
the number and direction of the shooting-stars ;
the northern lights, and similar phenomena,
might give some very useful indications concern-
ing the course and formation of the meteoric phe-
nomena, which cannot be foreseen with any fixed
degree of accuracy, excepting by first taking the
utmost care to collate and arrange observations
of every kind relative to the circumstances in
which they occur.

CHARACTER OF FUTURE SEASONS AND TEARS.

The attempt has been made to foretell the char-
acter of seasons and years to come, but the insuf-
ficiency of the data on which the prognostics
were based has, thus far, rendered the endeavor
nearly fruitless.

Nevertheless, M. de Gasparin reports that, in
1829, M. Hubert-Burnaud, of Yverdon, predicted a

CHARACTER OF FUTURE SEASONS AND YEARS. 281

severe winter for 1830, and it came as he had said.
" This was no prophecy," M. Burnaud tells us, " but
a very simple calculation. South and southwest
winds having prevailed for six months, I had a
right to suppose that the north winds would have
their turn. In the second place, the sun having
been hidden during the months of July and Octo-
ber, it was natural to think that the earth would
be cooled, at its surface, more than usual. This
circumstance, combined with the presence of the
north wind, should render the winter a very cold
one. Finally, the autumn having been very rainy,
the winter, according to all appearances, would be
dry. When all these circumstances are partial
only, no conclusion can be drawn ; but their gen-
eral prevalence, throughout Europe, would be
likely to produce simple effects, because there
would be no disturbing cause over an immense
extent of space."

Let us add that, in his important memoir on
the periodicity of severe winters, published in the
Annuaire de la Societe Meteorologique de France,
in May, 1861, M. Kenou, a learned meteorologist,
has grouped together all the observations recorded
since the year 1400, and has deduced from them
some remarkable results in reference to the peri-
odical return of severe winters.

282 METEORS AND METEORIC PHENOMENA.

" There will soon be an opportunity," says M.
Benou, " to verify the fact whether the periodicity
that I have announced for rigorous winters does
really exist, since the hardest winter of all is to
occur about 1861, and cannot, in my opinion, ex-
perience a delay of more than two years, as was
the case in 1709. Any postponement, I also be-
lieve, would be compensated b^ an exceptional
intensity of the season."

The winter of 1860 and that of 1863 and '64,
which covered southern Europe with snow and
ice, and was very severe even in Egypt, partially
confirmed M. Renou's predictions. We may be
permitted, then, to hope that the possibility of
foretelling the meteorological character of certain
years or certain periods, when based upon more
numerous and accurate observations, may one day
be sufficiently ascertained to lead to important re-
sults, particularly in reference to agriculture, the
leading source of our wealth and comfort.

SHOOTING-STARS. — INFLUENCE OF THE MOON.

"We must here mention the researches of M.
Ooulvier-Gravier, in relation to the shooting-
stars, whose appearance and direction enable us
to foretell changes of weather two or three days
in advance. The facts collated by this indefati-

SHOOTING-STAES. 283

gable observer in his work entitled " Researches in
relation to Meteors and the Laws that govern
Them," published at Paris in 1863, are sufficient-
ly remarkable to merit a serious examination, and
it is to be desired that the interesting researches
which he has taken up should be multiplied in
number, so as to ascertain their practical utility.
Moreover, we have already indicated all the im-
portance of these researches, which will aid us in
attaining a better comprehension of the limits and
constitution of the atmosphere, the first founda-
tion of a more exact knowledge of meteors, and
the laws that govern their formation.

The influence of the moon upon atmospheric
phenomena, the weather, and the seasons, ad-
mitted as it has been, by mariners, since the days
of antiquity, and occupying so large a place as it
does in the ancient collections of agricultural
maxims, was long denied by most men of learn-
ing, or regarded by them as too weak to produce
any appreciable results. It is, nevertheless, be-
yond all doubt that the attraction of the moon
and the sun, which produces the tides of the
ocean, occasions atmospheric tides, also ; and it is
very probable, indeed, that the latter may, espe-
cially at epochs when they are the strongest, de-
termine changes in the condition of the weather.
14

284: METEORS AND METEORIC PHENOMENA.

Experiments made with the utmost care, by
the aid of the barometer, have indicated the
totality of the movement imparted to the atmos-
phere by the phases of the moon, and the general
influence of those phases on the rains and on the
direction of the wind is now recognized. But it
is not easy to separate it for each place from the
secondary causes that tend to disguise it, and it
can be reached only by multiplying observations,
at present so very incomplete, with a view to
establish the probability of periodical variations
of the weather corresponding with the different
phases of the moon.

M. Arago, in a remarkable dissertation * rela-
tive to the influence of the lunar phases on at-
mospheric phenomena and the vegetable realm, has
established incontestable facts which, while de-
stroying errors hitherto accepted, still prove that
popular notions on the subject are not altogether
without foundation. When based upon real ob-
servation, they, on the contrary, may render good
service, unless they should become more injurious
than useful through the too great importance at-
tached to them. M. de Gasparin says, very justly

* " Annuaire of the Bureau of Longitude. 1832, 1833." See
also, in the "Annales Hydrographiques," 1st trimestre of 1864, the
note on Meteorology by Admiral Fitzroy

INFLUENCE OF THE MOON. 285

on this subject, that " there are scientific preju-
dices, as there are popular prejudices, but in no
age have learned men been more disposed to give
up theirs, and to submit them, in good faith, to
the crucible of experiment and observation. The
people themselves, too, no longer cling with the
same tenacity to their superstitious ^ideas, and
manifest much greater readiness to listen to the
voice of reason."

CHAPTER XII.

PRACTICAL METEOROLOGY.

The Brussels Conference.— Meteorological Practice.— Instruments of
Observation.— Telegraphic Meteorology.— The Hurricane of Decem-
ber 2, 1863.— Alarm-Signals.— Rural Meteorology.— Association for
the Advancement of Meteorology.

THE BRUSSELS CONFERENCE.

ADMIRAL FITZROY has collected, in an excellent
work called " The Book of the Weather," pub-
lished at London in 1863, the most familiar
notions concerning meteorology, and has made
known the combinations recently adopted in the
principal observatories of Europe and the United
States, in order to be able to give, either daily or
on the approach of storms, some rational an-
nouncement of the anticipated change in the
weather. We have summed up, in a work en-
titled " Storms," with very considerable fulness
of detail, the substance of what has been done, up
to the present time, to attain this important re-

THE BRUSSELS CONFERENCE. 287

suit ; and we have shown, by enumerating the
services already rendered, all that could be hoped
for in the early future. Returning here, briefly,
to the same subject, we are happy that we have
it in our power to bear testimony to the rapid
progress realized since the organization of the Im-
perial Observatory at Paris, a progress that leaves
no doubt remaining as to the rank that meteor-
ology is destined to take among the most useful
of the sciences, and those that are best adapted to
aid man in his labors, by giving him a more cor-
rect idea of the universal order that presides over
all things.

It is to a learned officer, formerly of the United
States naval service, Commander Maury, that we
owe the first idea of a great association to unite
all the most advanced nations in one common
system of meteorological observations, and in-
tended to include the entire globe, or at least all
those regions to which the light of science and
civilization has penetrated in our day.

A conference, in which the principal states of
Europe were represented, met at Brussels in 1853,
M. Quetelet, the director of the Royal Observa-
tory at Brussels, presiding. The object was, as
we have said, to come to an understanding in
reference to the adoption of a uniform system of

288 METEORS AND METEOEIC PHENOMENA.

observations at sea. Maury, who was then the
director of the National Observatory at "Wash-
ington, represented his government at this meet-
ing, and we here quote a part of his address, in
which he explained to those present the purpose
of his mission :

" The proposition, in consequence of which the
American Government has thought fit to call for
the present meeting, emanates from the English
Government. It consists of the communication
of a project drawn up by Captain Henry James
of the Royal Engineers, by order of Sir John Bur-
goyne, inspector-general of fortifications, and in
which the Government of the United States was
invited to take part.

" Nineteen stations have been established by
England, in pursuance of a uniform system, and
the observations have been placed under the im-
mediate direction of the officer of engineers com-
manding at each station.

" The American Government accepted the
proposal of the English Government, and, on
condition that the plan of observation should be
extended to the sea and made universal, promised
its cooperation. I was then intrusted with the
duty of placing myself in communication with
the owners and the captains of the naval and

THE BRUSSELS CONFERENCE.

mercantile marine, for the execution of the
plan.

" It was by the aid of information extracted
from more than a thousand log-books that I have
been enabled to prepare the charts of tracks,
winds, and currents, that have been published up
to the present time.

"In order to give still more extension to
nautical observations, the Government of the
United States has decided that an appeal should
be made to all maritime nations to induce them
to adopt a uniform model of log-book.

" The aim of our assembling is, therefore, to
come to a common understanding with reference
to a uniform method of nautical and meteorologi-
cal observations taken at sea. I am already in-
debted to the courtesy of one of the members
present, M. Jansen, lieutenant in the navy of the
Netherlands, for an extract from the log-book kept
on board of a Dutch man-of-war, and it may be
cited as an example of what may be expected of
expert and careful observers. In order to secure
regularity in the distribution of the charts that
the American Government offers gratuitously to
captains of every nationality, I would express the
wish that a person should be designated by the
government of each country to collect and com-

290 METEORS AND METEORIC PHENOMENA.

pile the extracts from log-books to which I have
had the honor of calling your attention. It is
through his hands that the charts would be con-
veyed to the parties for whom they were des-
tined."

We shall not here enumerate all the resolutions
adopted by the Conference, as we did in a work
entitled " The Phenomena of the Sea and the At-
mosphere," and more special in its nature. But
we think it right to recall the fact that it was the
starting-point for the researches which have ex-
tended so far since then, and have been the source
of important progress in meteorology. May we
not be allowed, at the same time, to remark that,
if the most wonderful of the Divine works, in the
order of material things, be the power of the laws
that maintain the harmony of the universe, there
is in the moral order no more gratifying subject
of contemplation than the laws which govern the
progress of communities, and which stand forth in
better relief in our day, in the happy tendencies
of Christianity toward association — in other words,
toward union of sentiment and effort ?

The Meteorological Bureau of Utrecht, under
the direction of M. Buys Ballot, a learned profess-
or, and established in order to centralize the ob-
servations made by the navy of Holland, was the

METEOROLOGICAL PRACTICE. 291

first establishment in Europe that cooperated
with Commander Maury's labors. Lieutenant
Jansen, a distinguished officer, who from the out-
set had applied himself with the most intelligent
zeal to the new system of research pursued on the
ocean, was attached to this bureau.

Belgium, Sweden, Norway, Denmark, Portu-
gal, Spain, the free city of Hamburg, and the re-
public of Bremen, soon followed the example set
by Holland, The British Government also was
one of the first to establish a bureau commissioned
to arrange and discuss the observations collected
by English ships upon all the waters of the globe,
in accordance with the plan recommended by the
Brussels Conference. Most of the great Powers,
also, had accepted this plan, and expressed their
intention to put it in execution, by means of
the vessels sailing under their flag. These, to use
Commander Maury's expression, would, for the
time being, have been made so many floating ob-
servatories, on board of which our common effort
for the advancement of science and the good of
humanity would be going on.

METEOROLOGICAL PRACTICE.

But it was easy to foresee that the ocean could
not remain the only subject of systematic study,

292 METEORS AND METEORIC PHENOMENA.

and Maury subsequently asked for another confer-
ence, with a view to proposing a plan of terrestrial
observations, " so that meteorology should be en-
abled, at last, to move onward in a path truly
universal."

It is evident that in this direction alone can
we hope to discover the great laws that govern
the movements of the atmosphere — laws of which
we now have but a glimpse, and the knowledge of
which would furnish the most solid foundation to
meteorological studies.

The nature of the researches necessary to
attain this result, not only demands the widest
range of observation, but those engaged in it
must be able to correspond with such rapidity as
to announce the appearance of phenomena, and
to follow their progress ; and the employment
of the electric telegraph has arisen to give mete-
orology this powerful means of investigation.

It is around the great lakes of America, where
disasters are so frequent, that this system of com-
munication was first put in play to signal the ap-
proach of storms ; adopted, subsequently, by the
principal states of Europe, it has already rendered
the greatest service to navigators, and should like-
wise aid in diminishing the losses that unexpected
bad weather so often inflicts upon agriculture.

INSTRUMENTS OF OBSERVATION. 293

Rapidly organized in England, thanks to the
zeal and devotion of Admiral Fitzroy, the system
of telegraphic warnings has been inaugurated in
France also, through the efforts of an illustrious
savant, M. le Yerrier, the director of the Imperial
Observatory. The ministry of marine in that
country has, also, on its part, decreed the estab-
lishment of a meteorological service in the sea-
ports, combined with the similar service in Eng-
land, and the recent construction, along the whole
extent of the French sea-coast, of signal-light
houses connected with the grand net-work of
electric telegraphs, admits of the transmission of
warnings to all the threatened points, and even to
vessels that may be passing in sight of the coast.
It may be readily understood how the generaliza-
tion of such a surface is as advantageous to the in-
terests of navigation as to the progress of science,
and we shall see this still more clearly as we take
up some details of the organization of meteorolo-
gical observatories.

INSTRUMENTS OF OBSERVATION.

Among the instruments of physical science
which serve to determine atmospheric variations,
the barometer is one of those that are most usually
consulted. All mariners have had the opportu-

294

METEORS AND METEORIC PHENOMENA.

nity to remark the usefulness of the indications

that it yields previously to rain and gales of wind.

But these indications, being relative to the weight
of the column of air that
causes the column of mer-
cury to oscillate, do not tell
us in what case that weight
increases or diminishes, and,
in order to arrive at a more
exact foreknowledge of phe-
nomena, it is necessary to as-
certain, by the thermometer
and the hygrometer, the dif-
ferent causes that may influ-
ence the weight of the atmo-
spheric strata. Thus, for ex-
ample, the variation of these
two instruments, especially
during the winter season,
may indicate, in the absence
of barometrical signs, the ap-
proach of cold and dry north
winds, or warm and moist
south winds,' the predomi-
nance of which determines
the character of the weather.

If these winds, in their general character, differ,

INSTRUMENTS OF OBSERVATION. 295

as Admiral Fitzroy thinks they do, and as we
should feel inclined to admit, in their electrical
condition, the indications of a curious instru-
ment entitled the storm-glass must not be neg-
lected, that condition no doubt having a great
influence upon the atmospheric phenomena, that
may modify the pressure of the atmosphere.

The storm-glass, used in England more than
a century ago, and taken up again by Admiral
Fitzroy, is composed of a glass tabe, hermetically
sealed, containing a chemical mixture, the aspect
of which varies according to the direction of the
wind, and not according to its force; that is -to
say, remarks the admiral, "according to the
special character, and very probably according to
the electric tension, of the aerial current."

We have had the opportunity to watch the
workings of one of these instruments for several
months, and we have often seen it indicate with
remarkable precision the violent storms of the
north, and the abundant rains that accompany the
great aerial currents of the south.

Still other instruments are employed in the
observatories, as, for instance, the psychrometer,
or damp-bulb thermometer, which indicates the
quantity of vapor in the atmosphere ; the pluvi-
ometer, which marks the quantity of rain fallen ;

296 METEOES AND METEORIC PHENOMENA.

the surface plate, by which the force of the wind
is measured through the pressure exerted upon it ;
the electrometer, that notes the electricity in the
air ; the prepared papers, by the exposure of which
to the atmosphere, and their subsequent compar-
ison with each other, the quantity of ozone or
electrified oxygen is ascertained through its prop-
erty of modifying their colors ; and, finally, certain
special instruments destined to indicate the mag-
netic condition of the earth.

TELEGEAPHIC METEOEOLOGT.

It is evident that the atmospheric condition
of any region is subjected to the influence of the
surrounding, and, in certain circumstances, to that
of other very distant, regions. An observatory
daily receiving, from all the chief points of a wide
extent of territory, like that which embraces
Europe and the banks of the Mediterranean, tele-
grams stating the condition of the weather at
each of those points, could not only preannounce
the atmospheric variations for the place in which
it is situated, but likewise for each of the places
with which it is in correspondence. Such is now
the position of the most important observatories
of Europe, and principally of the one in Paris,
which has been justly designated by Admiral Fitz-
roy as " a grand centre of telegraphic alliance."

TELEGRAPHIC METEOROLOGY. 297

This observatory now publishes daily a bul-
letin containing the data that are collected there
every three hours, as well as those that are fur-
nished to it at eight o'clock in the morning, by
about fifty correspondents distributed over the
whole surface of Europe. These data embrace
the barometric pressure, the temperature, the di-
rection and the force of the lower strata of winds,
the state of the sky, and the condition of the sea
upon the coast, at each station. Along with the
meteorological chart of the day, prepared under
the direction of M. Marie-Davy, is a summary
statement of the general character of the atmos-
phere, drawn up by that distinguished savant,
with a forecast of the probable state of the weath-
er on the ensuing day. These probabilities have
reference to fourteen regions, or districts, into
which the European seaboard has been marked
off.

Curves corresponding to the barometric press-
ure, divided by intervals of five millimetres, are
traced on this meteorological chart. The press-
ure of the atmosphere in Europe experiences fre-
quent variations, and it is in the proximity or
separation of those curves that the principal ele-
ments of a rational foreknowledge of the weather
are to be found.

298 METEORS AND METEORIC PHENOMENA.

THE HURRICANE OF DECEMBER 2.

This useful application of telegraphic meteor-
ology was scarcely realized when a terrible hurri-
cane occurred to demonstrate its efficacy. This
hurricane, which was analogous to the cyclones of
the tropical regions, swept across France between
the 2d and the 4th of December, 1863. Its in-
fluence was felt as early as the 28th of November,
the time when it was on the ocean, as high up in
latitude as the south of Spain. On the 27th and
the 28th the bulletin had already announced the
condition of the atmosphere as very doubtful.
Until the 1st of December, the whirlwind as-
cended toward the north, and was then signalled
from the northwest of England. " The rapid fall
which has been noted this morning in Ireland,"
said M. Marie-Davy, " the position of the curves
of equal barometric pressure, and the easterly
trending of the winds, which have gathered
strength in the south and southwest, show that
this phenomenon is inclining eastwardly, to strike
the coasts of Europe toward the north of England.
The storm, which will probably extend over all
France, seems likely to be severe." And, in fact,
on the morning of the 2d, the mercury fell with
extreme rapidity in England and France. The

THE HURRICANE OF DECEMBER 2. 299

whirlwind had then swept down upon the former
country, and had its centre near Liverpool.

As early as the 30th, the seaports from Dun-
kirk to Nantes had been forewarned by telegraph
that they were threatened with a gale. On the
1st of December, at noon, all the ocean -ports
were notified that a heavy storm, coming from
the southwest, was bearing down upon England
and France. Dispatches sent on the 2d will give
some idea of the activity that the meteorological
service displays in perilous circumstances :

"At eight o'clock in the morning, the storm
did, in fact, burst upon the north and a part of
the west of France. Paris and Bordeaux feel a
violent wind, but at Lyons, Limoges, and Ba-
yonne, the wind is still weak.

" At noon, all the ports of the Mediterranean
were again informed that they were seriously
threatened. Madrid received the same dispatch
in reference to the seaports on the Gulf of Lyons.
Turin was likewise notified for the north coasts
of Italy and as far as Leghorn. At fifty minutes
past one, it was repeated for the benefit of the
ports along the coasts from Civita Yecchia to
Palermo."

Admiral Fitzroy's telegrams had also notified
our ocean-ports in advance. They announced that

300 METEOKS AND METEORIC PHENOMENA.

the English coasts were covered with the warning
signals.

The Observatory of Paris remained for some
time without knowing whether its last dispatches
had reached their destination. Along several
lines the storm had prostrated the telegraph-poles
and broken the wires. But communication re-
mained open for a length of time sufficient for
the transmission of the most important telegram :
" On the 2d of December, during the daytime, I
received the two dispatches stating that a severe
storm was about to traverse France," writes the
president of the Toulon Chamber of Commerce to
M. le Terrier. " They were published and posted
up immediately, and the merchant-vessels in the
roadstead had time to provide, and did so pro-
vide, against all risks. The maritime prefecture,
on its behalf, directed all officers who were ashore
to hasten on board of their vessels. The storm
burst forth with all its fury about half-past three
o'clock in the afternoon. The first telegram sent
on the 2d, confirming that of the day before,
had therefore gained four hours' time ahead of
the storm, and every thing was ready to meet the
emergency. Thanks to the precautions thus tak-
en, there was no damage, no disaster to deplore."

The telegrams forwarded to Turin were im-

THE HURRICANE OF DECEMBER 2. 301

mediately communicated to the ports on the
western coast of Italy. The following note was
published on the 3d in the Giornale di Genova
(Genoese Journal) :

" The prediction of the Paris Observatory was
fully realized. The first signs of the storm were
felt yesterday about 7.30 p. M. During the
night it raged furiously ; but there appears, nev-
ertheless, to have been no disastrous occurrence in
our neighborhood. The commandant of the port
had hastened to take all proper measures, and we
may be thankful for them."

As soon as the principal ports of the Channel
and the Ocean had received the warning tele-
grams, they communicated them to the entire
coast by means of the electric signal stations that
have recently been established there. The num-
ber of disasters was, however, great enough in
those waters to cause surprise. Relatively to the
direction of the wind, which beat on the coast as
a general thing, it was more difficult to take pre-
cautions, and, on the other hand, again, there
must have been some negligence in regard to
them.

The best ideas penetrate the minds of men
but slowly, and there are, unfortunately, many
navigators still who do not take the warnings

302 METEORS AND METEOEIO PHENOMENA.

thus telegraphed to them seriously enough. For
a considerable period it required special instructors
in England to give sailors and fishermen more
accurate ideas on this subject.

The storm burst upon the northern coasts of
France with extreme suddenness and violence.
At Cherbourg, for instance, there was very little
wind and sea in the morning ; small boats could
navigate in the offing. The barometer, however,
coincided with the warnings given, in marking
signs of bad weather. At eight o'clock it had
gone down seven hundred and thirty-seven milli-
metres. At ten o'clock the storm came on like a
clap of thunder. Parts of buildings were knocked
down, and roofs torn off. In the roadstead, the-
sea was hurled aloft in whirling masses, and
formed a thick curtain of sprayey mist. Enor-
mous billows beat over the breakwater.

A pinnace, belonging to the iron-clad frigate
La Couronne, had set out to assist a merchant
vessel that was nearly in a sinking condition.
After reaching it, the pinnace was towing it in
to moorings when the storm burst forth with its
full fury. A small steamer from the port came
to its assistance for some time, but was obliged to
drop the tow in order to escape sinking itself.
The tide was running out, and, while the vessel

THE HURRICANE OF DECEMBER 2. 303

was borne onward to be wrecked on a less peril-
ous beach, the pinnace was carried out to sea. It
was lost to view, and in the evening two sailors,
covered with cuts and bruises, and both insensi-
ble, were picked up near Cape Levi. They had
but a confused recollection of the disaster, and
were the sole survivors of the boat's crew, which
was commanded by M. de Besplas, a gallant offi-
cer. The men were intrepid, and, led by a worthy
chief, did not hesitate to sacrifice their life in
order to accomplish an act of self-devotion and
humanity.

The reports from London declared that no
such formidable storm had been seen there since
1823. It everywhere presented the same char-
acter as at Cherbourg, excepting differences in the
direction of the wind and in the secondary phe-
nomena. At Strasburg, it was not until the 3d,
about four o'clock in the afternoon, that heavy
clouds covered the sky in a moment. Immedi-
ately, rain, snow, and hail, driven by a furious
wind, drenched the streets and squares. In the
south, on the contrary, a dry and cold north wind
blew a storm, at first under a clear sky.

The Observatory proposed to make a study of
this storm, as a totality, by means of the exact in-
dications procurable at all the stations lying with-

304 METEORS AND METEORIC PHENOMENA.

in its range. This study, the first part of which
was published in the Bulletin of March 31, 1864,
will, no doubt, be very prolific of results for me-
teorological science, as were the similar labors of
Admiral Fitzroy, after the great storm of Octo-
ber, 1859.

The theory of cyclones, founded by the Red-
fields, the Reids, and the Piddingtons, embraces
the general laws of their translation and rota-
tion. It has furnished practical rules for the man-
agement of vessels ; but it still leaves many gaps,
which the new studies of to-day, aided by the elec-
tric telegraph, will powerfully assist in filling. —
The point of view taken by the Observatory ap-
pears to us, moreover, excellent, and we earnestly
hope that the extension of the meteorological ser-
vice will soon render it possible to extend these
researches over a larger basis.*

" If our charts," said M. Marie-Davy, in a note
sent in to the Academy of Sciences, " enable us to
foretell a storm, and to follow it in its course
across the Continent of Europe, they tell us noth-
ing, or almost nothing, concerning the place of
their origin and their mode of formation, and nev-
ertheless that is one of the essential elements, not

* In M. Marie-Davy's interesting work entitled " The Move-
ments of the Atmosphere and the Sea, considered in reference to
Foretelling the State of the Weather."

ALARM-SIGNALS. 305

only of the science, but of its application. "We at-
tach the greatest importance to the construction
of daily charts, embracing the whole Northern
Hemisphere, were it to require a whole year to
bring together the necessary elements for each
one of them. In the midst of the incessant shift-
ing and changing of atmospheric phenomena, the
important point is, very certainly, to extract from
them great general laws, and the search for these
may be aided by the investigations of preceding

years."

ALARM-SIGNALS.

The alarm-signals employed in England to
announce the approach of storms consist, in the
daytime, of three figures made of strong canvas,
which are hoisted on the mast of the signal-sta-
tions, and can be seen at a great distance.

A cone, with the point turned toward the sky,
announces that there is some likelihood of a storm
from the north.

Placed with its point downward, the cone indi-
cates the approach of a storm from the south.

A cylinder is the signal for a hurricane or a
rotating tempest.

If the cone be placed with the point upward
above the cylinder, the storm that threatens
comes from the north.

306 METEORS AND METEORIC PHENOMENA.

If the cone, on the contrary, be under the cyl-
inder, with its point turned toward the ground,
the hurricane comes from the south.

During the night, lanterns, arranged as they
are seen in the accompanying illustration, in such
manner as to represent the cones or the cylinder,
take the place of the day- signals.

These signals, which are very simple, and of
easy manipulation, will, no doubt, be generally
adopted wherever the organization of the meteor-
ological service is such as to admit of the prean-
nouncement of storms.

On the coasts of the kingdom of Italy, mar-
iners are forewarned that a storm threatens them
by a red flag hoisted on all the towers and light-
houses of the principal localities, ranging from
Genoa to Palermo, and thence up along the Adri-
atic.

This signal is employed only when it may be
inferred from the meteorological Bulletin, sent by
the director of the Observatory at Paris, that a
tempest is approaching. The telegram that an-
nounces it is moreover posted up in all the sea-
ports, and transmitted to the Chambers of Com-
merce.

On the most dangerous points of the coast of
England, where the fishing-boats and small craft,

ALARM-SIGNALS.

p. 806

AGRICULTURAL METEOROLOGY. 307

that perform the service of the coast, are exposed
to formidable gales, even during the fine season,
barometers put up by the meteorological bureau
assist in foretelling bad weather. French ocean-
ports have received from the ministry of the ma-
rine instruments destined for the same service ; and
the recent adoption by France and England of a
code of signals that offers to all nations a uniform
means of communicating at sea, will enable ves-
sels provided with the necessary material, the
price of which is very moderate, to put themselves
in communication with the signal-stations, and to
receive the latest meteorological warnings from
them.

AGRICULTURAL METEOROLOGY.

M. le Yerrier — in his reply to the ministry of
Public Instruction, on the subject of the obser-
vations that it would be possible to organize in
France, in order to obtain data useful to agricul-
ture— recently said : " The reception, accorded by
our maritime populations, of the warnings fur-
nished them by the Observatory causes us to fore-
see the time at hand when our farmers will claim
similar attention from the solicitude of the gov-
ernment.

"Your excellency will, no doubt, remember

308 METEOES AND METEORIC PHENOMENA.

that it was the urgent request of Prussia, on be-
half of a society of agriculturists at Mecklenburg,
that gave occasion to our first dispatches predict-
ing the state of the weather, and that as early as
1854, after a storm that had devastated Provence,
after having raged at Havre twenty-four hours
earlier, the Agricultural Board of Toulon (Yar)
addressed a long letter to the Minister of Agricul-
ture, in order to set forth to him the advantages
that would result from the preannouncement, at
the right time, of the approach of bad weather.

" I think, then, M. Minister, that not only is
there fair occasion to encourage the good intentions
of the Normal School of Yesoul, which asked for
authority to have its pupils, under the direction of
a master, daily take meteorological observations,
to be published in the Journal of Practical Ag-
riculture, but that there would be great utility in
extending this measure to all the normal schools
in the empire. ISTo one would hesitate for a mo-
ment to take charge of this work.

"The instruments necessary for each school
are:

A barometer 80 francs

A thermometer 20 "

A pluviometer 30

An hygrometer 25

Total. . . 166 francs.

AGRICULTURAL METEOROLOGY. 309

" The agricultural societies, the rural boards,
and the , councils-general, could contribute the
means to defray this expense.

" Meteorology is taking a rank less and less
disputed among our sciences of general applica-
tion, and public attention is fixed upon the ser-
vices it is called upon to render to our people.
The moment seems, then, to have arrived for se-
rious effort in organizing the means of study that
are indispensable to it."

In a subsequent letter M. le Yerrier called the
attention of the Minister of Public Instruction to
the numerous tempests that crossed over Europe
during the month of May, 1864, and, in remark-
ing the fact that the storm-gusts of summer seem
to " have the same origin as the great tempests of
the bad season, and that both may be followed, as
well as foreseen, in their progress by the same
means," he asked the concurrence of the normal
schools, the Chambers of Commerce, the agricul-
tural societies, and government engineers, in get-
ting together the materials of a good statistical
statement of storms, that would render it possible
to prepare charts of the regions traversed by those
meteors, and determine the probabilities of storms
for each district. It will be easily understood
that such charts might not merely assist in fore-

310 METEOES AND METEORIC PHENOMENA.

warning farmers, but that they would, moreover,
present a means of proportioning the sacrifices
each individual would have to make, in a system
of mutual insurance, to his chances of loss.

In reply to this letter, the minister saw fit to
issue a circular to the prefects, asking the concur-
rence of the council-general of each department in
providing the necessary instruments, so as to put
the normal schools in a position to collect the ob-
servations indicated by M. le Terrier.

If we consider, as Messrs. Payen and Barral
have done, in their remarkable report * upon the
possible application of meteorology to agriculture,
all the advantages that would result to our rural
districts from a knowledge of the weather based
upon observations more certain than the usual
signs, we may hope that one day each of our vil-
lages, like each of our seaports, will possess the
necessary meteorological instruments, obtained
either by means of a moderate assessment or a
contribution from the townships and communes.
The tutor might be intrusted with the daily ob-
servations, which are easy to record ; and the in-
structions adopted f by the committee of the scien-

* Bulletin of the Imperial Observatory, number of July 19, 1864.
t Bulletin of the Imperial Observatory, number of August
25, 1864, and following numbers.

AaKICTTLTUEAL METEOROLOGY. 311

tific association, of which we shall mention the
organization farther on, would soon enable him
to foresee and preannounce, in most cases, the ap-
proach of atmospheric disturbances. Intelligent
property-owners, in associating themselves also
with these investigations, would not only obtain in-
dications calculated to aid rural pursuits : " They
will always be certain," says M. de Gasparin,
" of finding a pleasant and useful occupation in
meteorological observations ; in their comparison
with those of other places and other times, and,
while amusing their leisure hours, they will be
paving the way to the period when meteorology
will acquire the certainty of deduction which it
now lacks, and when conjectures relative to fu-
ture phenomena will become probabilities."

Let us add that the comparison of series of
observations made at different periods may indi-
cate, according to the just remark of M. Buys-
Ballot, whether the natural condition of the place
has undergone changes, in consequence of the
cultivation of the ground, or the clearing away of
forests, the drying up of lakes, arms of the sea, or
marshes, or by the replanting of woods. These
indications could not, undoubtedly, acquire a
scientific value, excepting by the lapse of time, but
they would be infinitely precious to us, should

312 METEOES AND METEOKIO PHENOMENA.

they go to confirm the influence that man may
exercise over the character of climate by a wise
management of the domain confided to him.

ASSOCIATION FOB THE ADVANCEMENT OF METEOR-
OLOGY.

The Meteorological Society of France, in pub-
lishing since 1849 a yearly Annuavre, or Calendar,
intended to comprise all the experiments and ob-
servations which had been but little known until
that time, and, to stimulate fresh researches, has
powerfully contributed to the progress of the
studies relating to a knowledge of the atmosphere
and of the phenomena taking place in it. Under
the auspices of this society, M. Eenou, one of its
members, has recently commenced a course of me-
teorology in the grand amphitheatre of the School
of Medicine. This course, in showing the impor-
tance of the new science, accessible as it is to all
ranges of intellect, will give a new impulse to the
useful research and to the interesting observations
that it invites one to pursue.

The zealous director of the Journal of Prac-
tical Agriculture, M. Barral, has brought about
the formation of a meteorological net-work based
upon the free cooperation of the farmers, and it,
in permitting the monthly publication of notes

ADVANCEMENT OF METEOROLOGY. 313

on the condition of the crops, at the same time
furnishes the best documents we have on the cli-
matology of France.

Finally, an important society for the advance-
ment of astronomy and meteorology has recently
been established under the presidency of M. le
Terrier. The following extract from the min-
utes of the first general sitting, which took place
on the 3d of June, 1864, will make known its
object :

" Astronomy and meteorology are making
rapid progress in the Old as well as in the New
World, thanks to the cooperation of governments,
individual action, and powerful associations ; nu-
merous establishments have been founded, and
great works accomplished, under this triple im-
pulsion.

" The French Government stands in the first
rank of those that give a liberal and fruitful sup-
port to science. The cities of Toulouse, and Mar-
seilles are erecting observatories, on their own
behalf, and the Chamber of Commerce of Toulon
has founded a yearly prize for meteorological ob-
servations at sea.

"The Association for the Advancement of
Astronomy and Meteorology has for its object the

314 METEOKS AND METEORIC PHENOMENA.

completion of the means of action at the disposal
of France." *

After this exposition, presented to the meeting
by M. le Terrier, the committee intrusted with
the first propositions relative to meteorology, rep-
resented by M. Renou, made a report, of which
we reproduce the principal passages :

" Meteorology is one of the sciences that were
cultivated in the earliest times. The diversity of
climates on the surface of the globe ; the changes
that daily take place in the state of the heavens ;
in the degree of movement, heat, and dampness
of the atmosphere ; and, above all, those great com-
motions of the air that disturb the surface of the
earth and the sea, concern our safety and comfort
too nearly not to have been interesting to man-
kind at all times.

" It belonged, however, to our day, in which
Science advances at so rapid a pace, and has at
her disposal so many resources hitherto unknown,
to give meteorology a prolific impulse by extend-
ing her investigations over the whole surface of
the globe, and associating individual efforts by
the rapid intercommunication of results obtained.

* This association counts more than two thousand members,
among whom are a great many ladies. An assessment of ten
francs per annum is levied.

ADVANCEMENT OF METEOROLOGY. 315

" The services rendered to navigation by
Maury, and by those who have striven to walk in
his footsteps, show that meteorology has entered
its true path. There can no longer be any doubt
that, by combined researches carried on persever-
ingly, upon a scale growing continually broader
and more comprehensive, it must attain a knowl-
edge of laws, as yet unknown, that govern the
motions of the atmosphere, and thus at last give
us the key of what we call the caprices of the
weather.

" The committee was struck with the impor-
tance of the position already given to meteorology
by the initiative of France, by the efforts of all the
nations of Europe, and by the eager cooperation
of all the managing boards of the telegraphic lines
of France and different countries."

After having made known the great interna-
tional meteorological service of which the Im-
perial Observatory of Paris is, at present, the
centre, M. Renou adds :

" An association of this kind is incontestably
a fact of great value, and the end at which it aims
is most important, since it embraces the preven-
tion of those disasters that annually cost the lives
of thousands of men, and the loss of millions of
property."

316 METEORS AND METEORIC PHENOMENA.

M. Renou then took up the question of estab-
lishing prizes, for meteorological investigations, to
be founded by the society. These prizes, three
in number, are to be bestowed upon the authors
of the best treatises on the general movements of
the atmosphere ; the best observations at sea ; and
the best series of observations made at places but
little known. Since then, two new prizes have
been instituted, to be given to the authors of the
two best treatises relative to the application of
meteorology to agricultural questions.

A chart summing up the service of nautical
meteorology, the centre of which is at Paris, has
been distributed to the members of the associa-
tion. This service, by which warnings of bad
weather are communicated, now extends to all the
coasts of the Baltic Sea, to that of the North Sea, to
the French coasts of the Channel and the Ocean,
to the coasts of Portugal and Spain, to the French
coasts of the Mediterranean, to those of Italy, of
Sicily, of the Adriatic, as far as Albania, and,
finally, to the Russian coasts of the Black Sea.

At the first session above noted, the associa-
tion voted an appropriation applicable to the con-
struction of a large telescope, to be put up in one
of the large cities of Southern France.

The links that unite astronomy, meteorology,

ADVANCEMENT OF METEOROLOGY. 317

and the physical constitution of the globe, were
treated with great elevation of views by Father
Secchi, the director of the observatory at Rome,
in a series of memoranda relative to the connec-
tion observed between the variations of the at-
mosphere and those of the magnetism of the earth.
M. Quetelet also, in his fine treatise on periodic
phenomena, handled those topics with ability.
The latter savant very correctly said : " Astron-
omy, and particularly the observation of the two
great luminaries that strike our gaze the most,
may be considered as including the origin of all
the phenomena that deserve to engage our studi-
ous attention."

Arago, in his " Popular Astronomy," has also
pointed out the beauties of the connection that the
observation of cosmic and terrestrial phenomena
reveals to us :

" The various phenomena of the starry vault
and of meteorology, even when they appear by
their fickleness to baffle all the perspicacity of
men, at length are seen, after profound study, to
be linked together in sublime coordination."

M. Renou, in his memoranda on the periodi-
cal return of heavy winters, has grouped together
the important facts that seem to prove that the
period of the principal meteorological phenomena

318 METEORS AND METEORIC PHENOMENA.

is associated with the periods of the shooting-
stars, the solar spots, and the oscillations of the
magnetic needle. These relations, although as
yet chiefly based upon conjecture, as M. Renou
remarks, must nevertheless be our guide in seek-
ing out the great laws that govern the organi-
zation of worlds.

It is, above all, by the knowledge of these laws,
by the admiration that they imperatively call for
in us, that it becomes possible for us to conceive
of the beneficent action of the Creative Power ;
to rise to the idea of Infinite Wisdom, and to
taste the ineffable peace of that religious feeling
which Leibnitz expressed so well when he said,
" It is no trivial thing to be content with God and
the universe."

NOTES.

mSTRTJMENTS OF OBSERVATION.

The Barometer.— The Thermometer.— The Hygrometer.— The Plu-
viometer, or Udometer.

THE BAEOMETEE.

AN upright tube of glass, of about 85 centimetres (3£
inches) in length, filled with mercury, and standing in a
cistern, or basin, also full of the same metal, constitutes a
barometer. The atmospheric pressure is measured by the
difference of levels established between the tube and the
receptacle. Various processes, more or less exact, have
been employed to determine this difference.

When no very great precision is required, a large recep-
tacle is used, and no attention is paid to the variations in
the level of the mercury that it contains. Sometimes it is
considered sufficient to make the scale movable, so as to
bring the zero of its subdivisions to the exterior level. In
the siphon barometer, the tube curved near the foot forms
two unequal limbs, the larger of which is closed and the
other open. It requires two observations.

Fortin's barometer, by which it is possible to take more
accurate observations, has the special advantage of being
very portable, but it is dear. It is distinguished from the
rest by the circumstance that the level of the mercury

NOTES.

in the receptacle can always be adjusted with much pre-
cision to the zero of the fixed scale. When the observation
is carefully made, the height can be attained within the
twentieth part of a millimetre.

Taking the precaution to compare it from time to time
with a mercury barometer, the aneroid barometer may be
employed in meteorological observations. It is composed
of a flexible brass tube, and is bent over in a ring that
nearly closes. A vacuum is made beforehand, and, when
the atmospheric pressure increases or diminishes, the ring
closes or opens, and this movement communicates itself to
a needle that marks the pressure on an index.

THE THEEMOMETEE.

The mercury thermometer is usually employed in the
observatories, and alcohol does not become necessary ex-
cept in regions where the cold congeals the metal/ The
liquid, the dilation of which is to be observed, is enclosed
in a capillary glass tube, soldered to a cylindrical or spher-
ical reservoir of the same material. The scale is graduated
on the tube itself, or upon a ruled register running parallel
to it, the former arrangement being the best. The temper-
ature of melting ice has been taken as the zero of this
scale, and for the second fixed point, represented by one
hundred degrees, the boiling temperature of distilled water
in a metallic receptacle, the atmospheric pressure being
Om.75.

In order to ascertain the lowest temperature at night
and the highest by day, special instruments are substituted
for ordinary thermometers. Eutherford's thermometer, a
minima, is the simplest. Placed horizontally, or very

INSTETJMENTS OF OBSERVATION. 321

slightly inclined to the side opposite the reservoir, it con-
tains alcohol and an index formed by a small enamelled
cylinder. When the liquid contracts, this body is carried
with it, by an adhesive effect, up to the point that cor-
responds with the maximum of contraction. The temper-
ature then rising, the alcohol dilates and passes between
the inner surface of the tube and the index, without dis-
placing the later.

The thermometer, a maxima, of the same inventor, is
also arranged with mercury, and encloses a cylindrical
index of iron. The instrument being placed horizontally,
and the fluid dilating, the cylinder is pushed before it. It
remains hi its place when the fluid contracts, because there
is no adhesion between mercury and iron. A magnet is
employed to reestablish contact.

The commission of the Scientific Association recom-
mends the thermometer, a maxima, of Messrs. Negretti and
Zambra, London opticians. It is a mercury thermometer,
the stem of which is choked near the reservoir by a
point of glass which is soldered to it inside. The mercury
passes this obstacle during the increase of temperature;
but when it is descending, the thermometer being hori-
zontal, the column of mercury is separated at the ob-
structed point, and remains in its place. When the obser-
vation has been made, it is sufficient to set the instrument
upright again and give it a slight shake, in order to make
the mercury fall back into the reservoir.

THE HYGBOMETEB.

When we speak of the hygrometric condition of the
atmosphere, we mean the relation between the actual

322 NOTES.

quantity of watery vapor that it contains, and the quan-
tity that it would contain were it saturated, the temper-
ature being the same in both cases. In order to get at this
relation, instruments termed hygrometers are used. They
are constructed in accordance with the property that
bodies have of becoming elongated by moisture and con-
tracted by dryness. Another mode of observing humidity
is by the psychrometer, which consists in simultaneously
watching two thermometers, the one dry and the other
with its reservoir kept constantly wet.

Saussure's hygrometer is formed of a hair previously
freed of grease. Its variations of length are communicated
to a needle moving on a marked dial. Zero is fixed at
the point where the needle stops when the air is com-
pletely dry, and one hundred degrees at the point it
touches when the air is saturated with watery vapor.
The indications of this instrument are not proportional
to the hygrometric condition of the air. In order to ob-
tain the latter, the tables prepared by Gay-Lussac must be
used.

In the psychrometer method, the evaporation that takes
place on the wet reservoir causes a decrease of temper-
ature, from which, by means of a simple calculation, may
be deduced the elastic force of the vapor, and, conse-
quently, the degree of moisture existing in the air.

THE PLTJVIOMETEE, OE UDOMETER.

The pluviometer, or udometer, is an instrument that
serves to measure the quantity of rain that falls during a
given time in a given place. Different forms might be de-
scribed, but one of the most simple is represented in the

INSTRUMENTS OF OBSERVATION. 323

Magasin Pittoresque, vol. xxiv., 1856, p. 192. Consider-
able improvements were proposed some years ago by M.
Herve-Mangon. The pluviometer of the marine depot, of
which we give an illustration, is composed of a double
reservoir of tin, with inclined planes, movable upon a cen-
tral axis, to serve as an overfall. The rain-water being re-
ceived in a wide funnel, the surface of which is determined
according to each apparatus, passes by a conduit into a
second reservoir A, above the receptacle B. The water
issues from it by a small orifice, and falls upon one of the
inclined planes of the receptacle. When a certain amount

PLUVIOMETER.

has flowed off, according to the condition of the apparatus,
the receptacle tips back, strikes against a copper stem 0 0,
and the water runs off into a lateral reservoir D D.

This tipping or oscillating movement recurs thus every

324: NOTES.

time that a sufficient weight of water has fallen. The prin-
cipal merit of the apparatus is, that it registers of itself the
volume of water received : for this purpose there is joined
to the horizontal axis E a needle F, the extremity of which
plunges into G, a small tank of mercury, every time that the
oscillating movement takes place.

During this very brief period an electric current is es-
tablished : it is produced by two wires, H and K, one of
which, K, communicates with L, the foot of the tank, and
the other with the mercury G. By means of a special
piece of mechanism, the current itself marks a point, each
time that the tipping occurs, upon a roll of paper that
passes on with a uniform motion. A glance at the sheet
will then let us know how much water fell at any given
time in the day.

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